I think it's better if you don't participate.

They're not going to face a player like you on the field, nor should they learn to rely on a player like you on the field, and there's no way you can see what's going on on the field if you're playing as accurately as you can if you stay out of the game.

Even if you are short of numbers, there are plenty of creative ways to practice skills that don't involve you playing.

Be their coach.

My advice, unrelated to whether or not you should play:

Throwing, throwing, throwing. These girls probably need no skill anywhere near as much as they need practice throwing and catching. Spend most of your practice having them throw in different situations. Have them throw standing still and after catching. Have them throw to stationary and moving receivers. Have them throw to cutters moving in and cutters moving sideways (only to cutters moving out for the ones that are ready).

Try to get them to throw on their own time, in a relaxed setting. Make sure each girl throws with people other than her good friends. Make sure rookies throw with vets, vets with vets, and rookies with rookies.

A drill I used to do with my rookies was: everybody pair off and stand 5 feet apart. Each throw you throw to your partner such that they don't have to move to catch it, they get to move back one large step. If the partner had to move, reset all the way back to 5 feet.

The nice thing about this drill is that it works for the good throwers and the bad ones.

Another simple drill: 10 complete flicks, 10 complete backhands, and 10 complete hammers. Teach your girls how to throw hammers; in my experience most young college girls struggle a lot with this skill.