My mother is taking over :(

Ive just turned 14 weeks, and have bought some things for the baby (just some vests and a onesie).

Last week my mother comes home and shes bought 2 onesies. I can deal with that.

Today i go round and shes bought the first bath towel, the first bibs, and more burp cloths when i told her i would buy them later on.

I feel like shes buying everything that i want to buy the first time. I know it sounds selfish.

Now i dont want to tell her the gender when i find out in case she goes and buys 100 outfits. How do i get her to back off without confronting her?