At the older teen ages teams are always losing players and looking for replacements. They need to carry very large rosters because there are always players missing with other commitments. Don't be discouraged by the timing, if she really wants to play and has some ability she will be able to add on to a team. The trick will be finding the right team for her. If she fell out of love with the game she wants a team that will rekindle that passion. When GWU did a study on retention in soccer out of 81 factors these are the top six kids said make soccer more fun:
If you can help her find a team where those things are top priorities that's the closest you can get to ensuring she has a great experience and wants to continue to play.
Most coaches will be happy to let her come to an open practice. If she can find a team with some friends already on it that may go a long way to making sure it's a positive experience--girls tended to rank working together with their team even higher than boys in terms of importance. If she doesn't know of any on a team she's willing to check out, start checking all the leagues and find out the teams nearby. If she's not comfortable calling coaches you can help. Once she is able to attend practices, don't just join the first team. That may be the one but go to a few others first to make sure. Watch how the players interact with each other and how they interact with the coach. Do they enjoy being together? Do they support each other and believe in each other? Does it look like an appropriate level for skill/ability? Will she be challenged? Will she be able to earn playing time?