make sure you are feeding her enough fat rich foods, not just fruits and veg. add in avocado, fish (if you can), chicken and meat, cheese, full fat yougurt etc. fruit and veg don't have many calories and at this age they do eat all the time and need calorie rich foods as well as good fats like in salmon and avocado, olive oil etc. both my dds ate constantly at this age, i couldn't keep them full. right now my 12 mo eats more than my almost 3 year old. it's a phase, you can't really overfeed them. i do try to keep it to 3 meals and 2 snacks and not a constant grazing thing all day. but maybe if you increase her calorie intake per meal and snack then she won 't be hungry in between.
for example my 12 mo ate today:
breakfast: 1/2 piece of raisin toast with cream cheese, 1/2 cup of blueberries, 1/2 cup cottage cheese
snack: 1/2 cup strawberries and 2 crackers
lunch: rice, 1 egg yolk, 1 yogurt, 2 baby carrots, blueberries
snack: cheese string, 2 crackers
dinner: 2 pieces of chicken (bite sized), 1/2 an avocado, 1/4 cup orzo, 1/2 nectarine, blueberries
2 cups of milk
she has baby chub but is not overweight - she's on the 50th percentile and she eats a ton. they go through phases and this toddler phase is an eating one!!