About the Annual Leave:
She will entitle 7 days for first year and the other 7 days for second year that total is 14 days for 2 years contract. In your case, you do not need to let her take 14 days annual leave in this vacation but if you plan to keep this maid in the next year and will renew her contract. That's fine.
About the Air Ticket:
You only pay One Way Air Ticket for your domestic helper come to HK and One Way Air Ticket for her back to her country after finished the 2 years contract. Except these, you do not have liability to pay for any kind of air ticket for your domestic helper during her vacation.
About the "regnancy":
Any neutral agreement is no use. You should ask her to sign a resignation letter for assurance. Of course, you must examinate her urine of pregnancy test after she back one week. Once the result is Positive, her resignation letter will work then.