K.B.
I agree with S.M. go through the clothes and put together whatever you have that you really don't want anymore or that you KNOW came from her. Tell her that's all there is and let it go. On the baby shower she has no right to tell you what to spend. Are you throwing her the shower? Then it's up to you as the host, not her as the guest of honor. If she doesn't like what you are planning to do for her shower tell her that you're sorry but you won't be able to throw her a shower like she wants and perhaps she has other friends who can throw it for her.
Good luck,
K.