There are just about as many dog food brands as there are dogs! I've tried various kibbles from high end to Purina. High end foods seemed to cause a LOT of noxious gas emissions that caused our eyes to water. I've been feeding our 2 boxers Purina One for years and they're doing great. Gypsy is 11 this month can Cody was 7 last Dec. They're fed just under a cup 2x/day. I would not let her free feed. Bulldogs tend to be pretty round to start with and she might get way too heavy if allowed to eat all she wants when she wants.
You'll have to experiment to see what works for your girl. You may want to stick with the protein that is in the canned food if she's doing well with it. Switch her slowly by mixing a small amount of kibble with her canned, then gradually increase it over several days. She may not like it but she will not starve and will eat what you feed her as long as you don't cave! I know those big sad eyes can make us do things we don't want to. ;)