I take it no potatoes or crackers (yeast free) of any kind? Sugar, honey? Onions, garlic?
The rice or millet can be used to make a stuffing/dressing for the turkey with poultry seasoning. You can use pears and cranberries to make a chutney for a side. You'll need some kind of sweetener, whether it is honey or sugar. If you can find some of acid (usually vinegar or lemon juice) that would make chutney taste better. Maybe just a splash of white wine?
You can make mashes with parsnips and any of the hard squashes (butternut, acorn, etc), besides cubing them and roasting preferred as it gives more flavor than steaming. Butternut squash soup | Paleo Leap
. If she can have eggs (even just yolks) or egg substitute, you can find recipes for dessert using pumpkin and coconut milk.
You can sub out turkey for the duck in Spiced Duck Breast | Paleo Leap
. Might have to leave out the mushrooms and leek (onion family). I'd serve it with rice or millet spiced with 5-spice powder.
I LOVE rack of lamb cut into "lollipops" and grilled. I usually rub them with a mixture of garlic, oregano and olive oil first and let them sit for a while. You could make a mash with the parsnips and maybe grill some romaine since you'd have the grill going anyway.
Slice up green/yellow squash and layer, dotting with butter and S and P in between layers. If she can have Ritz crackers, crush some of them and sprinkle in between layers. Also, thinly slice onions and put in layers too if she can have. Top with dotted butter, crushed crackers, S and P, cover and bake at 375 until almost done, then uncover and let dry out/brown on top just a bit. Time will vary depending on how thick your casserole is.
Since you say you are a newbie cook, I'm just going to mention some things that are available that you might not know about like rice noodles (quite a few types), rice flour, coconut milk (NOT the super sweet stuff you make drinks with).
You might want to check out glass/cellophane noodles to see if she can eat those just for a change of pace. Maybe a stir fry type dish with turkey, parsnips and one of the hard orange squashes, cumin, cilantro, touch of heat with cayenne or chili powder if you don't want too spicy.