Shaz, our moderator, may have some knowledge about Pouchkins - she's had an ileostomy for a long time and has been around these forums.
The only thing I can recommend is to try using part of an Eakin Seal, which is made of a material similar to the "sticky round part that goes over the stoma". This Seal is stuck to the area just around the hole where the stoma goes through the sticky round part to provide an extra seal or barrier to prevent leaks. I really don't know much about the Pouchkins, but just assume they are a smaller version of what we adults wear.
I sure hope that you find some answers here, and please, feel free to post with Any questions you might have. How is your daughter doing with her ileostomy?
Welcom to HW.com,
Diagnosed with CD in 1979, many resections and meds
Perm Ileostomy July 1984 at Cleveland Clinic
Disease free since surgery