7yo girl is extremely picky (in home)

hi there,I want to ask for your advice. Since some time I'm in a relationship with a girl who has now a 7yo daughter.The problem is that the girl is extremely picky - show won't eat a lot of things. Even if she want's a tomato soup - if the soup won't look exactly like the one made by her grandma - she won't eat it. Same goes with sauces. She likes pastas and for example spaghetti but won't eat it as long as the sauce looks exactly like one made by grandma.The problem? Grandma is a terrible cook. I mean - she doesn't cook much but use all "fix" things - like bought powdered sauce etc.Even then when she cooks something oftentimes the girl won't eat - so it's not like she eats only "what grandma made".But in preschool? (she turns 7 in few days, so she will go to school this september). She eats a lot - she always comes back with stamps all over her arms, those stamps are given to children that eat a lot etc.Even if for example she gets something in home - she says "I hate it, I won't eat it" - the next day if she gets exactly the same meal in the preschool she will eat all of it.She rarely goes on the deal "just try it". If she only "hears" a name of something she instantly doesn't want it. Even if she haven't try it. Or even if she eat it a lot in preschool.She ends up eating plain pasta, plain rice. Because anything else, she won't eat. Sometimes she gets something like nutella but I deliberately "forget" to buy a new jar. That's because if she goes into stubborn mode - she won't eat anything else except the thing she wants - usually nutella, chocolate etc.I try avoiding pushing food into her and try to at prepare things she want's from time to time. Except I don't use premade powder things like her grandma - but no matter how good the sauce, she won't eat it because she sees a too big piece of onion, or soup is a bit too dense that what she eats etc.Sometimes she eats a ham with a garlic sauce.What I wish is know how to make her eat something more nutritional - I can prepare separate dish just for her but this is pointless when she won't eat it via /r/Parenting http://ift.tt/2mQJC65