Yes, it's imperative that she tries them on, as peoples feet are so variable.
Get them measured, and try on many different shoes.
'Diabetic' shoes are really unneccessary, any comfortable shoes will be better. Look for something with a good support on the arch, and a whole, not open, toe. Other than that, it doesn't have to be dull in the least.
Comfort for HER feet is the biggest priority.
I've been wearing New Rock shoes for over 10 years. They're definitly not to everyone's tastes lol.. but they're good quality and suit my feet.
Never order online, unless you've already got a pair, as you can't be sure they'll be good for your feet.