Consider getting her an old, second hand sewing machine from eBay or Craigslist or garage sales.
That's if you can find one. Take your time and wait for one. Those old sewing machines from the 1960s to the 1970s are in high demand and for a lot of money nowadays. Those machines are made of ALL Metal and do not break down as the newer plastic, and worse: plastic and run by
computerized components do. The ALL Metal machines are true work horses. They sew through thick fabric and densely woven fabrics like 6 layers of denim (along seams and over hems) at the same time, like a hot knife slicing through a frozen stick of butter. Whereas the computerized or electronic machines will jam up on many fabrics. Especially if she wants to sew different types of fabric and different weights of fabrics together for costumes.
Also, if one lives in the snow belt and wears thick winter clothes, a new "light duty" or "starter" sewing machine will be nothing but frustration.
When you read reviews or the sewing machine description, most people will say whether a machine is capable of sewing through several layers of
heavyweight denim jeans or not. That's usually the benchmark for how heavy duty the machine is. There are some lighter weight chambray cotton materials that some people think of as denim because of the color, or very lightweight, summer clothes are made with it. But it's not really the heavyweight denim jeans material. So, if more reviews say it doesn't really sew through several layers of denim, go by them.
A new computerized sewing machine that is capable of going through thick or many layers of fabric are called "professional level" machines and they can run $500 - $1200. Whereas, if one finds a 1960's machine in working condition (that basically only needs oiling and a tune up,) at Goodwill or eBay for $150 - $200, that is a STEAL! They may not do all the fancy stitches a computerized machine is created for. But, for altering, repairing or sewing heavy, thick clothes, they are the bomb!
Just make sure it can do the zig-zag stitch. The zig-zag stitch will also sew over side seams when necessary to stop certain fabrics from fraying. But, a good pair of pinking shears stops most of that. If it is capable of using a button hole attachment, great. But, it's really not that hard to learn to do one totally manually with the zig-zag stitch.
Here is an old DIS thread where I talked about how I threw out my old machine when the motor caught fire, instead of simply replacing the motor. I was so happy to get a new machine capable of 36 fancy stitches, only to hate it so much as it wouldn't do "basic" sewing repairs, that I ended up searching eBay for months until I was able to buy my exact same old model again. I didn't want any more unpleasant surprises. That old machine was so reliable. That post was 12 years ago, and I still stand by it!
https://www.disboards.com/threads/j...kenmore-sewing-machine.3032436/#post-46911756