I am single, work full-time, and do a lot for my parents. Although cooking isn't one of them. I 'prepare' and serve them, but I feel guilty that I don't make them a home-cooked meal. I don't have the know how and the few times I tried, I can't say it's to their liking anyway. I want the best for them and this is one area that I lack. They are not starving and are well taken care of, but I wish I could always do more. We tried a home delivery service and they didn't eat it. They like things the way my mom used to make it and certainly no one can mirror that. I feel bad about the simple meals, or the ordering in, and canned or frozen foods.
Your doing wonderful, and everybody have different "talents". Im sure your food is good, but look at it this way. Your doing everything else, and so what if you have to order in, make canned or frozen foods and simple meals, you need help too. So this way your still feeding them, they are still eating healthy, and you have a little more time on your hands!
Cooking homemade meals, esp from scratch is not easy, so no worries! No, do not feel guilty! Hugs
Another idea is to have your mom teach you how she cooked things or get on Allrecipes and start reading and practicing a few recipes. I love to cook and bake and have enjoyed making many things for my parents. But I'm a vegetarian, so my dad never got me to cook the meat he enjoyed, I'd just buy it. But it could be a bonding experience for you and your mom, if she can still remember how to make things.
But food is just one part of caregiving. Don't beat yourself up if you're not able to do that part "perfectly". None of us do everything perfectly. And even if you did, they might still not appreciate it (my mom just doesn't eat much anymore, even my homemade stuff). So do the best you can and know that it's enough!
It could also be that your parents feel bad about no longer being the ones "in charge," and they're complaining because it makes them feel better about themselves by comparing your cooking unfavorably to your mom's.
Simple meals aren't bad meals, as long as they're nutritious. There are a lot of recipes online that are easy to make and taste delicious. Quinoa with grape tomatoes, cilantro, diced mozzarella, and balsamic vinaigrette dressing takes about twenty minutes to whip up, and it's very good. Since you work full-time while helping your parents, you're already got a lot to keep you busy without worrying that you're not Gordon Ramsay.
There's such a thing as looking a gift horse in the mouth, and it seems like that's what your parents are doing. I would love it if someone came to my house and made my meals, simple or not.
Do they like smoothies? They don't require chewing, and there are lots of healthy recipes online. With fresh fruit in season now, your parents might like them,
much love.