What ever you are comftable with and likethe results of, the 50mm looks like a good lens to use because the results you've got with this is great.
If  you use the kit lens you might suffer from distortion making her have a big nose, if you use the telephoto you might suffer from camera shake and is quite a hand full to hold when in awkward positions. Brillaint shot with great soft lighting.
Andrew

I think Andrew is spot on with his suggestion - whatever you are comfortable with!!!  I think this portrait is great - the most important thing with portraiture is making your subject feel comfortable - cos if that doesnt happen, then it doesnt matter whether you have all the expensive lighting and lenses!  She seems very comfortable with you - so spot on - cheers JO

Super shot, Janet. Excellent composition and super light. I'd have though the 50mm would make an excellent choice for a portrait lens. I guess the result seems to show this.  Cheers, Col.

Andrew, Jo, Colin, thanks for the tips, usually only use this lens for very close work but I do like how this has turned out, so in the future I'll be putting this lens to more use.
Janet

The 50 in good hands Janet, and the result tells us so, well done.  (may be nice also in mono)

Donny

Thanks Donny will give it a go.
Janet