Baby Shower... Maybe?

My SIL brought up the idea of throwing a baby shower for me to my MIL. My MIL said yeah they can do it, but she doesn't know that I know anything about it. I'm starting to get anxious. I want to start packing a hospital bag and get everything ready for baby Abbi to join us, but I'm missing a few things. Like I don't really have any newborn clothes or diapers and I was hoping to use her diaper bag for her stuff and a small backpack for my stuff. I haven't asked any questions about the baby shower because my SIL told me that my MIL wants it to be a "suprise". I just hit 26 weeks and I'm dangerously close to having gestational diabetes. Baby Abbi also is measuring a little on the bigger side and my 5 year old said he just knows his baby sister will be here early. How many weeks is normal for the baby shower? I don't want to push too close to due date because I'm worried about being induced early and not having time to get stuff I might still need after the shower. Should I start asking questions about when the shower will be? I'm pretty sure the only talk that's happened is that it will happen, but no planning has been made and no people have been contacted. I don't want to sound like I'm ungrateful, I just want to be prepared. Like if it's not gonna happen I'm fine with that I just need to know so I can get the stuff I need. But if it is gonna happen then I need to know when so I can get the stuff I might still need after it... Especially when we plan to get the high dollar stuff with our taxes. So yeah 2 questions... Should I ask when/if the baby shower will be happening? And is 26 weeks too early for a shower or what week should I wait for if I'm worried about early labor?