Margarita cake

Hi! I’m new to the forum and need some help. My sons girlfriend has ask me to make her 21st. Birthday cake and she wants it to be a margarita! I really want to be able to surprise her with this came but need thoughts, suggestions,tips, on now to support the cup part of it to keep it from breaking when only being supported by the stem! Please help me I’m running out of time. I’m by far no professional decorator and have never tackled anything like this one but it means alot to me that she ask me to do this for her. Can someone please be so kind to help me out I don’t work with fondant I never learned that and she ask that I didn’t use it because she doesn’t like the taste so I guess it is good in l e respect but maybe not in others! Thank you in advance I’ll anxiously await any help anyone can offer.