YMS tier 5 to different visa?

Hi,
My husband is a Canadian citizen in the UK on a tier 5 youth mobility visa. It expires June 2015.
I was wondering if anyone knows if we can apply for a spouse visa before his visa runs out? We meet the income requirement. We also have an 8 month old daughter, she is a British citizen. If I'm right doesn't this mean she's exempt from the extra income needed for a dependant child?

Any advice you can give would be very gratefully received. Thank you

Sorry, I didn't search thoroughly enough when I posted this. I've now found a different thread which answered my questions.