I have two basic aluminum telescopic ones and they are great and have lasted for years. You can get a nice one with a travel bag for around $25 on Amazon.

Pick up a nice Manfrotto from amazon or Best Buy. 100-150 range.

Amazon Basics for $26:

https://www.amazon.com/gp/product/B005KP473Q/ref=ppx_yo_dt_b_asin_title_o05_s01

Zero issues.

Or this one: https://www.amazon.com/AmazonBasics-Lightweight-Camera-Mount-Tripod/dp/B00XI87KV8/ref=sr_1_1_sspa

There are 3 types of tripods.

1. The useless rickety ones that will hold a camera, but it won’t be stable, making it completely ineffective.

2. Good, solid, but unfortunately a bit pricey tripods that will do the job for decades.

3. Insanely overpriced, but still good ones that are really specialty items for upper level photo and video.

I owned a few from category 1. They never really did the job. Then about 15 years ago I firmly entered category 2 with a Manfrotto 055XB and a 484RC2 ball head with quick release plates. It’s a lot heavier, so I’m very aware when it is along for the ride. However, the thing is solid. I never worry about the camera or the lens I put on top of it. I love that I can set it up on very uneven ground and get a good solid platform to work from. I use it for still photography. And the first thing I noticed was that little wobble of the crap tripods was gone. So it was easier to get sharp pictures. At first I thought I had paid too much for it, but after a couple weeks using it in the field, I decided it was the exact correct gear for me. Staged shoots like a couple hundred portraits in an afternoon were just easier with the right gear.

As for your niece, it all depends on her needs and how long she will want to use it. Any tripod will simply hold a light camera. As long as she knows the limitations of the really light cheap ones, they may work. But they shake if disturbed at all. If she is really young, a cheap one might be best. But if you get something that will work for decades, maybe that isn’t bad either. I’d just stay away from the category 3 stuff, because $600 tripods even shock my senses still.

Induro makes some good tripods as well. They have all styles from beginner to professional. B and h and adorama have specials on them from time to time.

What DaveH said.
With tripods you get what you pay for.

The $25-$50 base versions that people link to, are good enough for a compact camera or light dslr with small lens.
By what you describe this is enough for what she needs - to keep the camera still while filming.

Just know its limitations. Put a heavier camera or zoom lens (say everything more than 100mm) and it won't be stable.
Don't expect to take pictures of the moon or wildlife with it. That's not what it's made for.

If she would get interested in photography, and wants a stable tripod to use with a zoom lens - then you need something like a Manfrotto and you're in $100-$150 or higher category. A good tripod like that is an investment that you enjoy for the rest of your life.

My Manfrotto tripod was a few hundred dollars twenty years ago. I still have it. It is still rock solid.

You can't go wrong with the Manfrotto suggestions, and I've also still got my entry level Velbon that I bought almost 40 years ago for about $100 - it owes me nothing and is still rock solid. Their current Sherpa model is just north of that price point.