I would like some advice please!!

I have three cats at the moment (2 brothers aged 1.5yrs and a male 7month old kitten). I have had a call from the rescue centre I got them all from saying they have had a huge intake of kittens in the last week and wondered if I would be willing to take another one?

I absolutely love cats and would love to take another one but I am not sure if 4 cats would be ok? I live by myself and only have a 2 bed house. The three cats I have at the moment are all outdoor and the 7month old kitten we think is deaf.

Does anyone have any advice on this??

This would very much be appreciated.