I forgot to reply back to you. Ashley received her tape early last week. She has been doing the exercises on a daily basis and says she definitely can feel them in her abs. Thanks!
The handstand is the FOUNDATION of her handspring. ANY error in the handSTAND will be MAGNIFIED in the handSPRING and other handstand based skills. Keep her working on them. If you aren't sure she's doing them EXACTLY right, I have a video EXCLUSIVELY focused on the basic handSTAND position.
Abdomen strength is a general body tension exercise. Body tension exercises are important for holding a straight body throughout the handspring, but the WRIST and ANKLE exercises are CRITICAL for protecting those joints, and the SHOULDER/KNEE (jump) exercises are vital for POWER. Make sure she works DILIGENTLY on all the strength exercises.
There are many MANY subtle lessons in that video that will only be absorbed through MULTIPLE viewings and ACTUAL participation in the video. Think of it as homework for her tumbling and keep her on a regular daily regimen for best effects.
Have fun, be safe push HARD!