We do a lot of work on learning man to man defense. We do drills and practice in different game settings however when it comes to actual games, my girls struggle with help side defense. Any suggestions or drills you guys use to improve this. Thanks.

I would suggest doing more 5 on 5 during practice and using film of your practice/games to make corrections.  Maybe your or one of your assistants concentrate on coaching this particular part of your defense during practice/games until you get better at it.