tl;dr: etiquette for 3rd baby shower/sprinkle? (and how to best convey to host)

Background: I'm pregnant with my third, a boy, after 2 girls. My first 2 were born out of state, across the country from family and friends (we moved 3 mo before the first was born!).

My mom is very excited that she gets to be present for this third baby pregnancy/delivery and wants to throw us a shower. I feel like it will be lovely to celebrate this baby, and finally get to have a "real" baby shower with my family, but I feel like it's a little tacky to have a baby shower by #3. I've already tried to gently introduce the idea that this should be small (a "sprinkle") and more celebration focused. But my mom is really into doing the full, get presents, invite everyone in the universe shebang (luckily I don't know that many people, but she even had old high school friends on her suggested guest list ). Like I don't want to invite my mom friends from nearby because it will be in my hometown and I don't want to ask them to drive 1.5 hrs when they have little kids like me! My mom is also easily offended so I'm trying to scale/refocus her energy without ruffling her feathers, which is not easy...she drives me crazy at baseline and we don't communicate well. But I can tell this is important to her.

Any advice?