monsterland wrote:
Redirect this toward making her a template of a girl you're looking for, instead of being THE actual girl you're looking for. Once you make this clear to yourself and draw the line, you'll stop feeling guilty.
Absolutely! There are traits the OP finds desireable, and unfortunately she's already taken. The best thing which can be done is to understand why you like her, use that motivation to make yourself better and,
a) heaven forbid, she becomes available...
b) you find a suitable replacement...
you're prepared.