I wouldn't go with "did you lose my number? :p text me" or "hey what you doin right now?" .
I hate it when girls text me saying something pointless like "how was your weekend?" or "whats up?" I know demonstrates interest and I'm usually okay with it the first time they do it but if you don't know the person well and they send me that I only reply if I'm really interested, so its kinda risky.
Next time cut it short, you would have been much better off not sending the last text and waiting a few days to text her back. I always cut it short.
If it was me this is exactly what I would do:
I would wait till the weekend and send her a text saying
"I just saw this dorky family of three all wearing bumbags together! haha For some reason they reminded me of your dancing buddies

are you out breaking hearts again this weekend?"
What ever she replies try to either not reply or if she asks a question or you think of a good reply to what she said go for it but maybe go with something closed ended and that is obviously ment to be the last text, like ending with "well, have a good one". Sending the last text and cutting it off letting her know your not expecting a reply is DHV in my opinion.
Then wait till sunday arvo and send "I know we only just met and I shouldn't ask you this yet since we hardly know each other, but you've already told me how sexy you think I am so I'm just going to ask you... can I have one of your livers? haha

I think I partied way too hard this weekend, mine are about to quit on me

How was (whatever she said she was doing that weekend in the other texts)?.
Try to cut the convo short again, let her send the last text.
wait till wedensday before sending another, unless she texts you. Make it interesting, say something like
"you kinda owe me one now, since you did give me that liver." or if she said you could have it say you owe her one.
and that leaves it open for her to suggest what that favour could be or she will ask you what it could be... be creative, if she indicates anything sexual go with it, you need to read her or if your not sure..
say something like, "Normally, I would repay you by taking you out for a magical date where we would share a milkshake then go for a walk on the beach, but I'm still a little sore from the operation, so your going to have to wait till I'm feeling better haha"
let us know how it goes, or if anyone wants to suggest what's wrong with my approach please, criticise away.