Should I get a kitten for my cat?

Lately, our 7 year old female snowshoe has been a little lethargic and sad. She used to be an outdoor cat but has settled into her indoor life mostly well. She doesn’t seem to be great with other outdoor cats but I am considering getting her a Maine coon kitten.

How would you go about finding if they may be a good fit together or is it just a “let’s hope and see” kind of thing? Any advice would be greatly appreciated.