As DanMaz stated there is no value in being a "switch hitter" but there is always value in speed on the left side of the plate or, power from either side of the plate.
If your DD has above average speed it makes sense to stay on or, go too the left side and drill drill drill to improve. If she is of average speed and more comfortable on the right side stay there.
Over the years I have taken many ladies 14 and above and worked them to the left side so they were more serviceable to our team at the HS level and several ended up with additional opportunities beyond HS.
Moving to the left side depends on the player though and, their dedication and support from parents to making the switch.
I had some ladies that were .200 or lower hitters with a lot of Ks that could have been more valuable on the left side choose to stay on the right side and get spot playing time in HS because they did not want to put in the time to get better.
I had another lady though that was a junior when I took over as coach and embraced the switch and lead the team in OB%, second in BA%, lead team in SB. She ended up a Skyline player of the month and NFCA HS honorable mention so if the player has the tools and dedication they can make a switch when they hit HS.