Met an HB8 in a club on the night of the 22nd and number closed (she asked for mine and immediately texted me a smiley. I responded the same night to say "nice to meet you" etc with a kiss at the end.

Sent her a mid morning 'Merry Christmas' text on the 25th saying it was nice to meet her on the 22nd. Her response included "it was great to talk to you last Thursday" and closed off with another smiley face. Pretty positive in my eyes.

On the back of the positive response from her I thought I'll see if she fancies the hook up. The HB is a doctor and working irregular hours so I texted her on Christmas night asking of she would like to meet up once she has got her current series of night shifts out the way. NO RESPONSE!!!

Upon self review I reckon I have probably failed to build rapport and jumped in too early in trying to set up a day 2 but how do I go about salvaging this?

in your texts, just to ask open-ended questions so that she gives you more information to work on to extend the interaction. and depending on the info she gives you, you have to decide which direction to take it, whether it's attraction or rapport building.