I could be wrong but I don't think pumpkin seeds is a "good thing" for bunnies..?
Switching her to healthy good bunny food may be too much of a shock for her so be sure to go slowly so her digestive system can adjust. Even though she's not eating well, to flip a switch would be too much. I'd try to get her some high fiber timothy based pellets for her right away and start to incorporate a little with the 1/8 bag you have left of whatever she's eating, then step it up every couple days until she's totally switched to something good.
Hay would definitely be good - I know some buns have a hard time eating if they haven't been in the habit of getting it. Some buns love it and take it up right away.
Iceberg lettuce is just crunchy water. It doesn't offer any significant nutritional value to a bun, so I wouldn't bother with that. Start her one veg at a time, to make sure she takes it ok, give her some bunny safe veggies like romaine, kale... If she's not drinking, sprinkle some water on top of the greens if she likes to eat greens.
Her eating routine may just be adjusting... if she's not eating/drinking at all then it might be concerning. If she's just nibbling a bit, it is probably normal adjustment period funk working itself out.
She is so pretty and adorable in your 2nd picture. I am really amazed at how much better she looks in your care. Poor baby's toes... it's so sad to read that she was so neglected. It made me pretty mad to read about her condition. Her previous owner should get some kind of reprimanding for her animal neglect.....