Hi. My name is*****'m looking at your question now and will post my answer or ask for more information here in a short while.
You say the gift is without reservation. So, why would there be a possibility of a gift back to you?
So long as there is no definitive agreement (certainly nothing in writing) to return the gift so to speak you should be fine. Its perfectly acceptable for a gift to be made by your daughter to you if she can afford to do it and you need help sometime in the future. People's circumstances change and family members help one another out.
I hope this helps but let me know if you have any further questions.
No, it would not be liable to tax.
Recipients of gifts don't pay tax on them. Take a look here for information on Inheritance Tax.