Can I say,

(a) My sister likes knitting. She is doing / making / ... (got any other suitables words?) cross-stitch when she is free.

(b) My sister likes sewing. She is doing a / doing cross-stitch now.
Hi Vincent.

Knitting and cross-stitch are different types of crafts.

(a) My sister likes knitting. okay

She does cross-stitch when she is free. - okay with "does." Or "She works on her cross-stitch project when she is free. (Don't link it to the knitting sentence because they are different things.)

(b) My sister likes sewing. She is doing a / doing cross-stitch now. Okay - I guess "cross stitch" is a type of sewing.
Hello VT,

With cross-stitch, you embroider cloth that has already been marked with a pattern or the outline of a picture. You use small fine needles like this:

With knitting, you create a garment or toy out of wool, with larger, blunter needles, like this:

Best wishes,

Students: We have free audio pronunciation exercises.
What are difference between knitting and cross-stitch?
 MrPedantic's reply was promoted to an answer.
Students: Are you brave enough to let our tutors analyse your pronunciation?
Both are kinds of needlework. Here are some things you can say:

My sister likes many kinds of needlework -- knitting is her favorite, but she also does cross-stitch and embroidery.

She knits all the time.

She is always working on a project.

She likes to do crafts -- needlework, origami and jewelry-making are some of her hobbies.