I have been thinking about getting my cat a dog but I’m not sure if it’s a good idea.

I have a 7 year old cat. I’ve had her since she was 6 months and other than a two year period where I had a roommate we generally are the only ones in the house. So she hasn’t interacted with a lot of people or other animals. She is very attached to me and has some anxiety issues. I was thinking about getting a second pet so she would have a friend. I was thinking about getting a small to medium size dog because I think she would get jealous of another cat. I’m not sure is this is a good idea or not. Has anyone else been in this situation?