My 93 year old mother has trouble eating--her dentures don't help with biting and chewing. How can I make sure she gets enough protein?

You can try the ready to drink protein shakes by Premier protein. They are very low carb (which is important at our house) and actually tasty. Sams club and Costco carry them in many flavors. They have 30 grams of protein each.
Hope this helps -
Sparkles

Completed vegetable protein consists of lentils (ie all types of peas and beans) taken at the same time as grains. Peanut butter on bread is completed vegetable protein, for example, and even better with dairy butter spread on first. There are many many recipes for bean dishes cooked with spices and served with rice. Mash half the beans (half the tin), leave the remaining beans whole to be more interesting, add a few diced tomatoes and frozen peas. There are huge numbers of variations, particularly if you include dairy – cheese, yoghurt and cream. Look for vegetarian and vegan cook books. If she misses meat, try diced or minced meat cooked in the slow cooker until it's really soft.

Are they doing a lining so the dentures fit better? If not, ask for one, they can help make them tighter.

You can do smoothies and add protein powder or nuts to increase protein, do some research on veggies that add protein as well. Red beans and mung beans are soft and good sources of protein, actually all beans. Eggs and cheese are good sources and soft.