No, don't necessarily remove the lettuce. If that is primarily what she is choosing to eat now and hardly any pellets, you don't want to remove her main food source for now. I had a baby bun that wasn't weaned properly from it's mom, and the only food she would eat at first was dark leafy lettuce, and a lot of it, because that's what the previous owners had insanely weaned her on instead of regular rabbit food and hay.
First, are the pellets you are feeding the same exact brand and type she was getting in her previous home? If not, that may be why she isn't eating these new ones very well, and I would suggest getting and feeding her the exact same pellets she was getting before. Rabbits can be very picky about food changes, and it's also not a good idea to be changing a rabbits type of food suddenly, particularly recently weaned baby rabbits who have a very sensitive digestive system and are prone to developing harmful digestive illnesses. Do you know any other foods the previous owners were feeding her, like a grass hay instead of alfalfa?
If you don't know what pellets she was getting and can't find out, or what you are feeding now are the exact same as she was getting before, then when she was weaned from the mom, do you know if she was for sure eating pellets and hay well? If the previous owners didn't wean her properly and make sure she was eating solid food well before you got her, that could be the problem you are having.
Also, baby rabbits this young often don't mind being held and may even like it as it simulates snuggling with their siblings. So if she is used to people and seems comfortable with you holding her and isn't scared, I would continue to spend time with her and hold her. It actually may be very comforting to her and help her not feel so stressed in a new home. But only if she isn't acting scared or fearful. If she will fall asleep in your arms or on your lap, she isn't scared.