You should leave her alone and move on. It's not proper for you to have a relationship with her, she is your relative's employee and doesn't have the freedom to see you, and you should respect her person enough to admire her without trying to win her affection, as it is unfair to her. Please move on and look at other girls.
Be nice to her, try to engage her in conversation (gently at first) to see if there's any interest on her part. She may be wary because she works for your aunt, but if she likes you at least she ail show that with her smile and eyes.<br />
If you're only staying a short while, ask her if you can write/call her when you return home. If you really are interested in her for more than a quick romp, be prepared to take it gentle and a longer play...<br />
If you just want a holiday fling, go for it but don't take it to heart if she says no. Good luck!