Hi Amber, my two guys are 18 months old, and they weigh 45 lbs each, my vet says they are slightly overweight and should weigh 40 lbs. she says it is better for their hips and their joints, and for future health of them. They don't look overweight, but she says it's healthier for them. My two are on the smaller size for bullies, they're mother was also small, Brynnlee may be a bigger sized bully, every EB is different when it comes to size and weight. A good way to tell if your EB is overweight is too feel their ribs, you should be able to feel the ribs, but not see them, and if you look at your EB from the top view, they should have a well defined waist that goes in a little.
We feed our two guys Fromms Beef Frittata, twice a day, they get 1 cup in the morning, and 1 cup in the afternoon. I would try cutting back her food to two 1 cup feedings a day from her current 1 and a half cups. 2 and 1/2 cups seems like too much food for her. You can still give her 1Tbsp. of yogurt everyday, as this is good for the probiotics and digestion, and it boosts their immune systems. You can also give her veggies on her food, like green beans, broccoli, or cauliflower to help fill her up, as these are low in calories, and she can still have her treats of occasional fruits such as banana, strawberries, blueberries, watermelon, and such, but just one of these a day, as fruits are high in sugar.