I'm sorry Marci
I hear where you are coming from for sure, I was completely behind the curve, but in the last few weeks have gone completely crazy because I NEEDED to get every little thing that I'd need for him RIGHT NOW!! I had a small baby shower 3 weeks ago, and was going crazy waiting till after that to buy the rest of the stuff...
And, you are a planner much more so than I am...
Is there any way that you can talk to her and explain that you really appreciate her doing the shower, but asking if it would be possible to do it before the baby is here, and explain exactly why...because you want to spend time focused on the baby after she is here instead of setting up furniture,. cleaning clothes, etc...and maybe if she really wants to have one after, you could have a post-baby shower also (not a gift shower though), so everyone who was at the shower can meet the baby???