Foot Swelling/Shoe Size

Brittney • I`m 32 years old and have a almost 2 year old son (bday 9/3) and pregnant with our little girl (due 10/4)
Hello! My BFF is getting married and I will be 35 weeks pregnant at the wedding...and I'm in it of course. She wants all of us to wear the same shoes. She's picked out a strappy wedge that's low. My feet did swell pretty bad with baby number 1. And it's going to be a hot outdoor wedding. 
Should I get a 1/2 size or full size bigger? I am hoping to wear these shoes for the ceremony and pictures then plan to switch to something comfy.
Note: the bride TOTALLY understands if I can't wear the same shoes, but I still want to try!