Hi, I wonder if someone can please help me and give some advice on show jacket sizs for my dd. I am a complete novice and am slightly confused. She may have her first show on Sunday, late notice, I know, and I don't have any jacket or jodhpurs. I have had a look on eBay and her chest size is 29/30" ish. Does she need to get a bigger size to fit her body protector under her jacket? thank you.