Dress for baby shower

Tanja • My husband & I are so excited for our sixth child. Our kids are 16,15,12, 4(the boys) daughter is 5!
So I'm a procrastinator and I just got this dress yesterday from the clearance rack (lol) to wear for my baby shower. In this stock photo it goes to the models ankles on me it brushes tops of my feet. It is very comfortable! My problem is its kind of a thin material you can see through it. I don't feel like everyone seeing my panties on Sunday, baby shower is outdoors and it will be nice and sunny out. Anyway my question is; would this look okay if I paired it with a cardigan and if so how long would be okay? I want a cardigan because I also just do not like my flabby arms that I have had for years now. I know I shouldn't care but I want to be comfortable at my baby shower and not worry about how any pictures my end up looking. You know what I mean. Lol help please?!? I have no fashion sense. Lol