(it's) little wonder
It is not at all surprising (that something is the case). I was always terrible at math in school, so it's little wonder that I have such trouble filing my taxes. Little wonder you had such trouble starting the car: the battery is almost completely dead!
it’s no/small/little ˈwonder (that)...
it’s not surprising: If you walked all the way, it’s little wonder you’re late.‘The heating’s gone off.’ ‘I thought it was cold. No wonder!’