I wish I could help you! I have no experience at all with females in heat - let alone Toy Breeds

I was frantic because the vet told me Remy was getting very close and we all crossed our fingers, toes and paws that she was able to be spayed when she was - because Max is in tact... we're planning on breeding him if he continues to do well (we're working on getting him ready for AKC Hunting Trials!) ...
Anyway - so off topic - sorry... I'd probably check with the Vet too, just to be sure all is well.
How is she behaving while in heat? Are you noticing any obvious behavioral changes? I'm just curious...
Keep us posted - I'm interested in finding out if small breeds have longer estrus cycles...

How long has she been in heat?