My disabled daughter needed a nanny until she got into an inclusion out of school care centre (she wasn't allowed in regular). Do I claim as medical or daycare expense?

You should claim it as daycare for her. (This is assuming you have working income)

Daycare is actually a better credit because it comes off your income dollar for dollar while medical is a %. 

If you have no working income such as a pension or WSIB, the childcare will not make a difference but the medical may. So basically it could go on either but daycare is the best choice.