I haven't had this experience, but if it were my kid, I think the consequence would be that the social engagements she was planning would be cancelled. She isn't allowing YOU to be the mom and make the plans in this situation, and this is worrisome. If she's trying to go around you in making plans now, what's this going to look like later on?
If she 'isn't trusting you' to follow-up with friends' parents, I would change how that communication is happening between you and your daughter. Let her know when you intend to make the call/text and ask her 'why don't you give me until tonight/whenever to ask me that again. That would be a good reminder if I haven't done it. ' Let her know you want to do this for her.
Or, you can always tell her that if she wants you to drop what you are doing and make social arrangements for her, she can trade you jobs. She can help her cause by doing the housework you might be occupied with at the time she asks. "Sure, if you want to do some dishes, I'll have a few minutes to call/text so-and-so's mom."
I suggest these things, not to diminish your frustration and concern, but so you have a positive way to address what your daughter is perceiving to be a problem. Giving her positive options to getting what she wants means that she is also MORE on the hook for going behind your back and using the phone.
I'd also let her know that if it continues to happen, I'll have to ask her friend's parents to contact me directly via phone to make arrangements since she is making plans via text which I haven't agreed to. It would likely be pretty embarrassing to her, but it would be for her own safety.