Hi, pure_angel! It’s very thoughtful of you to seek comments from others in hopes of getting the best model for your mother! Thumbs up!
If you can afford one, I’d recommend a mixer on a stand–one that can be lifted off the stand when only a hand mixer is needed and can have the base adjusted so that the beaters will be in the center or at the edge of the mixing bowl, while the mixer is turned on. If your mother mixes big batches, she’ll enjoy that type because its heavier motor can stand up to large, thick, stiff batters more easeily, whereas, with a hand mixer you have less motor power and can hear the extra strain of the motor, feel the struggle within the vibration as you hold the mixer, and even smell the motor overheating. Kitchen Aid is a work horse, but a very expensive one! We have a Hamilton Beach on a stand that has been in our family for more than 69 years and is still running ok, although we did send it back to the factory for repairs in 1955, and have replaced the cord two other times because the cords were getting “stiffish.”
I’ve burned out three hand mixers–making butter, frosting, and fudge, BUT, I’ve really enjoyed my Sunbeam and GE models that I’ve had for years. I much prefer a model that has a release for the beaters, but make sure that the release can’t be accidentally engaged while using the mixer–the button should be placed so that you definitely know when you’re engaging it. The more speeds, the better the mixing can be controlled with different consistencies. Go with the highest horsepower available.
There’s a third type, the immersion blender/beater, which is a big, fat electric stick that fits down easily into pans on the stove or into a large mug or glass, and is designed for minimum mess.
Kohl’s, Penneys, Macy’s, and hardwares generally have dependable brands. Comparison shop in different stores, including the “big box” variety, as prices vary widely, and you should be able to get a real deal the day after Thanksgiving. Consumer Reports Magazine and Cook’s Illustrated Magazine may have performance evaluations, too. The three that I ruined are brands that are often found in big box stores and drug stores, but seldom in the other stores that I mentioned. Good luck to you! No matter what you pick, your mother is going to be thrilled!