Susan
I really hope you find a home for the cat and her kittens - I had similar situation when I was there (Sunbreeze) in December. I "adopted" a 9-week old black & white kitten (we rescued it around 3 times from being lunch for a couple of dogs!) that I called Felix. I fed him up real good, got him house-trained, tended his bad eye so it was just fine before I had to leave. Fell for him hook, line & sinker, and just couldn't leave him without trying to get him a home. If you can, try and get in touch with Bron Eastwood, or Eileen from the San Pedro Sun. They are involved with the Saga Society, and are trying to (a) get homes for the stray dogs and cats; (b) trying to spay/neuter them; and (c) trying to set up an animal shelter in SP. I noticed they have a link in from the main AC website, where you can make donations too(which are very very much needed!).
They really helped me and found a good home for Felix before I left (I am embarrassed to say it broke my heart to hand him over and I was in floods of tears - what a sucker!), and they do have other kittens to find homes for, but they are your best bet - unless you luck out and get a response from someone else in SP. I know how you must feel at leaving town and the kittens; if I could have got Felix home to England without him suffering the long journey and 6 months quarantine (and my 3 cats at home), I dearly would have loved to keep him.
Also, Sandshaker (Tammi)is very much a cat person, with kittens to find homes for too, so she may be able to get involved too.(Tammi, hope you don't mind me suggesting you!) And Anabel at Capricorn Resort was kind enough to ask around her customers too!
Please let us know how you get on?
Marilyn (a fellow catlover)