Lingerie shopping with mother in law? #not having a lingerie shower

Yup. She wants to go naughty panty shopping with me. A little backstory: my fiance is an only child (and my older brother's best friend!) and I come from a huge family of 8 kids. I've been friends with his mom since I was about 4 years old, and we are close, but for some reason she has it in her mind that we are going to be "best friends" when fiance and I are married. She brought up the convo about lingerie and asked if my mom was going to take me (um... no? Is she supposed to?) I told her that my bestie and I were going. Then she said several times that she would "love to take me." Umm... Is it just me or is that awkward? Then I texted my friend and begged her to go with me hahaha. She finally dropped it when I told her every time that bestie and I were going together, but then for my bridal shower(no lingerie) she got me a large sum gift card to a lingerie store. Is this awkward\weird, or am I just thinking too much? Why would I want her helping me pick out lingerie for her son?