Vegetable kabobs, either grilled or baked, and kept warm on a hot tray or in a chafing dish. Use any of the following: eggplant cubes, mushroom caps, small potatoes (fingerlings or baby potatoes, or chunks of larger red potatoes or sweet potatoes), zucchini or yellow squash (cut in 3/4 inch cylinders), green or red peppers (cut in 1x1 inch pieces). Thread them on wooden skewers (soak them in water ahead of time so they don't catch fire!), and mix up the order so that they don't all have the same vegetables. That way a guest can avoid a food he/she doesn't care for. Put 4 or 5 veggies on a stick, that's all. You can coat them with any herb/oil mix you like. I use a lot of dill because it goes well with many vegetables but you can search around for what you like. I just put the skewers in a baking sheet, mix the oil & herbs in a tall glass that can hold a basting brush standing up (easy to put both in the dishwasher afterwards), brush a little oil mix on top, turn and brush again. You can brush again during cooking/grilling, turning once.
A favorite because it looks good on a party table is a fruit kabob "porcupine" - wash the rind of a watermelon (seedless or regular), scoop out the fruit, turn over the half shell and drain. Meanwhile, cube up the melon and other fruits of many colors (other melon, kiwi, berries, grapes, pineapple). Get those plastic cocktail picks that have an arrowhead point on the end rather than standard slim toothpicks. Thread 4 pieces of fruit on picks, mixing up the order for a colorful array. Poke holes in the outside of the watermelon shell with a sharp knife point or a metal skewer, and insert fruit picks into those holes so the fruit all sticks out at different angles like a porcupine. Put on a platter with some paper towels to absorb any remaining melon juice or surround with greens like lettuce or kale leaves.
Falafel - make your own or use a mix, making balls or flatter patties, keep warm and serve with a tahini dip on the side. These can be made ahead and just heated up and served warm.
Hot cheese puffs - assuming she eats eggs and cheese. Split up and toast English muffins (a pack of 6 muffins will yield 48 little appetizers). Spread the 12 muffin halves with a mix of mayonnaise, shredded cheddar or jack cheese, and any spice you want such as seasoned pepper. (You can also give it a Mexican flair with a taco cheese mix, an Italian flair with half mozzarella, etc.) The proportions don't matter but I probably use 1/2 cup mayo to 1 cup shredded cheese. Just mix until it holds together. Spread this paste on the muffin halves (almost but not quite to the edge), then take a sharp chef's knife and cut the muffin rounds into 4 wedges. Put on a baking sheet. This much can be done ahead of time. To bake, put in the oven at 375 for about 10 minutes until the cheese/mayo puffs up and gets golden brown. Watch them so they don't burn. Put on a hot tray or on a platter to pass. Honestly, people think you slaved!
Quesadilla wedges: spread a flour tortilla with refried beans, then add black beans or other small beans (or rough chopped kidney beans), diced green peppers, chopped tomatoes (drained and seeded), some frozen corn kernels - don't even bother to defrost), and some Mexican style cheese (taco cheese, Monterrey Jack, etc.). Top with another tortilla and bake until the insides are hot and the cheese has melted, sticking everything together. Remove the completed quesadillas from the oven and use a sharp knife to cut wedges like a pizza. Try not to move them around too much or they may come apart - just put the whole circle on the platter and then cut. These make great finger food. You can also use very small tortillas and just fold them over in half so they are a half-moon shape, then cut in half - that way each one has a folded edge and the insides don't slide out. But be sure you use a flexible tortilla and not the kind that splits/breaks when you fold it.
Lettuce wraps or stuffed vegetarian grape leaves.
If you have a good market with prepared party foods, go browse for ideas!