I should also add that DS was also a catnapper during the day so I'd been through all the 'try patting them back to sleep' etc suggestions and it never worked. All it achieved was making me more anxious. I used to complain that he only napped for 40 minutes at a time, then I had DD and it was 20 minutes tops. As she was fed to sleep that was usually enough time to:
1. Realise she is fully asleep and I might be able to sneak away
2. Put the kettle on to make a cup of tea
3. Chuck a load of washing in the machine or put a few things away in the dishwasher
4. Make the tea
Oh! Too late, she's woken up. No time to actually drink the tea, time to feed her again.
There was one freak day where she slept for the entire day pretty much, and she wasn't sick either. 'twas bliss.