just a couple tips to look for or work on- (and yes i hate pitching machines!!!!! only for learning how to bunt properly and work on bunt direction bat angles stuff like that.)
1) 2 eyes
2) chin chin or Mike and Ike. mike = front shoulder Ike = back shoulder
b4 pitch have to have two eyes forward (use front chin on front shoulder to make sure her nose isnt in the way of her back eye = no depth perception) you can test this by asking her get in your normal stance look at pitcher b4 she pitches and stop. now close your front eye....... are you looking at your nose or can you see the pitcher?) if she sees her nose her head is not forward enough and focus on MIKE - chin on front shoulder prior to pitch.
now after tracking ball to contact finish with chin on back shoulder " IKE " helps keeping eyes on ball until after contact, staying closed and helps get to proper extension. We teach this simple technique at an early age so it becomes consistent and habit. then if we see it in a game you simply yell Mike an Ike!! they will get it. I love those candies too!
good luck
DanMaz is right, the technique is sound. Getting your daughter to understand and execute-----------jury is still probably out on that one! I'm not trying to be mean but habits are just that, habits. It's hard to change. You're going to get a lot of ideas from coaches using different terminology and odds are 1 will get thru and she'll get it. She may still get it but can't execute it yet. There's a couple things to remember; She knows she has a problem. That's over half the battle. You're trying to help her. Nobody is in denial here.
First; Be sure to follow StedmanOO's advice and have her vision checked. Eliminate the obvious first.
DanMaz shared some key words in the shared instruction that your daughter needs to really focus on. Her head location and positioning. He spoke of her nose, her eyes, her shoulders, and the relationship of all during set up and completion of the swing. The other word of interest is "tracking" the ball. In my honest opinion, what you described as your daughter's problem I believe this issue is probably her problem.
She is unconsciously staying on the body form (meaning the pitcher) throughout the pitch or at minimum too long after pitcher's release. This leaves her late to track the ball into the hitting zone. Here's where many can debate my theory on the problems with pitching machines and tee's compared to live pitching. Pitching machines can unconsciously give you sense of security because most of the time the path of the pitch (and speed) is so predictable. She doesn't need to be spot on tracking the ball and can be late to track because she already knows in theory where it's going to be when her eyes finally catch up to it. Locking into the flight of the ball sooner gives her brain more time to decide on the pitch and actually react to swing. A lot for a brain to process in less than .5-second.
Hitting tees can also give the same sense of security for like reasons. There is no perfect way to "fix" the problem but a combination of everything can provide her with the repetitions with a structured practice format to retrain the brain to track the ball from release to the zone.
Let's test my theory. Get you a bag full of those plastic golf balls in 2 different colors. Stand in front of her about 10-12ft with p;roper safety practices and fastpitch underhand to her. Once in a while, fake her out and don't throw the ball. If she is complacent in your practice drill she'll start to swing prematurely even tho you never let go of the ball. An initial reaction can be expected but if she's throwing the bat deep into her swing or taking a full swing, you have proved my point. Fix this first. Next, tell her to only swing at the orange balls. Hide the bag from her, randomly reach in and throw her a ball. Be sure to let the other colors go by and watch them fly past her. This will help many things including the tracking of the ball. Next, call out a color to hit and mix it up. Don't look yourself. That way there's nothing premeditated. lol. Next my favorite is the bean toss. Get a bag of beans, I like kidney beans but lima beans work good. Underhand toss beans at them from 10--12ft. If they can hit a bean, they can hit a softball. Beans are biodegradable and feeds the birds during the week. Encourage the hitter to not only swing but swing and hit it hard. Whether it be beans or plastic ball, swing to hit all of them you're supposed to regardless of the location. Be sure you wear safety glasses cause she will learn to do this. Fun game, fun practice, great training drills.
A couple or more things come from the drills. Now it's time to be a coach. Observe how she swings in the beginning and watch her adjust her swing to her advantage. She'll shorten her swing. She'll quicken her swing. She'll adapt to the situation. All from the repetitions. A luxury she does not have when in a game situation. Why???? Habit.
Many girls have the prettiest swing while hitting off a tee. Textbook, beautiful flow. Really look and analyze the swing there and compare it to how she adapts to the unpredictable circumstances in the drills. She needs to adapt in the batter's box and utilize the skills she uses in the drills.
Now, here's how this normally goes in the transformation. She won't be swinging as hard and not hitting the ball as hard. What will happen is she'll start getting good clean contact. She may foul them off while she adjusts her timing but they'll start coming off the bat cleaner. Encourage her to expand her strike zone.She needs to start "thinking out of the box" a little and adapt to a flight of the balls being somewhere else than belt high over the middle of the plate. Don't let a bad plate experience be discouraging. Have her analyze what happened so she can mentally start making adjustments. It's not a wrong at bat if she learns from it. Remember; if you are right 3-4 times out of 10 in this game you could be in the Hall of Fame someday. 30-40% makes you a hero. What is really key is contact quality. If you're outs are still hard hit balls you really didn't miss. You simply lost that battle. After she gets some confidence she'll pick up and swing with more power. It's a progression that takes time as well as repetitions.
Honestly, none of us can truly help without seeing her actually hitting. You can't really tell anything from a video unless it is something blatantly wrong in her form. Everyone above shared valid points of interest. Some of what I shared is just another approach to help you solve a problem that plagues hitters all over the world. Good luck----------be patient..........