First Question would be is it a National Qualifier or NIT?
NSA has always given a great deal of discretion to it's local organizations, my suggestion would be to e-mail the State Director and give him the particulars.
In reviewing the NSA bylaws I am confounded by the "she cannot play in the Championship game" statement, either she can play in the Tournament or she cannot, for all organizations that I am aware of it doesn't matter how many games in the event she plays in or whether they were Pool, Bracket or Championship games. It looks like she must be added to the teams online roster and in every sense be registered with that team, I wish these things were all easier, I have pasted on info from the NSA Fastpitch Bylaws available online at PlayNSA.
Unless approved by the National Headquarter or Zone Office, the National Softball Association Official Roster must be entered online with all information correct and complete or the player(s) and/or team(s) will be considered ineligible to participate in any National Softball Association sanctioned Tournaments, including Qualifiers, NIT?s or Championship Play Tournaments. Roster will be frozen by the date of the State tournament
Teams must PRINT a copy of the Official NSA ONLINE ROSTER, OBTAIN SIGNATURES of parent or guardian (18 years and older must sign for themselves) to turn in at ALL NSA sanctioned tournaments prior to their scheduled start or they will not be allowed to participate
GUEST PLAYERS 1) If a team uses a guest player and plays in another state, they have to play under the guidelines set in the state they are playing in. Not all states may offer this program. Contact your State Director. 2) Request must be approved by the State Director or his/her representative 24 to 48 hours prior to the start of the tournament. 3) The State Director or his/her appointed representative must also receive written or electronic approval from her current coach 4) A player can only guest play maximum of two (2) times per sanctioned season.
Having suitably muddied the waters, I will offer common sense would dictate that it is a fall event and just let the kid play, if your intent is for her to play with her 12u team in the upcoming season and to qualify for or play in an NSA National I would recommend crossing t's and dotting I's, you would be surprised where problems in this kind of thing generally come from.