Ok set food times could help. At day care we do morning tea at 9.15, lunch at 11.30, Afternoon tea 2. You may find this helps. I have to do this on school holidays with my kids who are all older than yours, but similar workings - morning tea 11.30, lunch 1, Afternoon tea 3. Nothing else. Oh and padlocks on the doors of the fridge freezer and pantry. Had to do that cause the pockets couldn't afford the food bill.

some suggestions to discourage emotional eating:

• keep her hands busy when you see that she isn't doing anything (crayons, puzzles, etc)
• encourage talking about her feelings by teaching her many feeling words: feeling blue, happy, bored, sad, excited, etc.
• ask if she's hungry so she can identify the feelings of hunger and encourage the use of the word full
• use chore chart/schedule chart - much the same as in preschool or daycares:  include times for breakfast, snack, lunch, snack, dinner.  At my son's preschool, snack times are the same across the board for all ages (except infants): 10 and 3:30
• replace junk foods with healthy snacks. Maybe if she eats as much fruits as she wants, she may be too full to eat junk food
• have the same snack/meal time as her and you can have it as together time

Our girls are the same.  They will eat if food is in reach, even if they have just eaten.  Trying to keep the food out of reach can be a difficult task, but is the only way we have managed to stop the banana raids!  We also have safety locks on the pantry door so they can't just help themselves to what's in there either.

As for emotional eating, I don't know how to deal with that in toddlers, hard enough with adults.