BTW, I haven't last night's ep yet so no spoilers please!
But doesn't Rita have a son, about 8 yrs old? We've seen her at home loads recently and there is no evidence of him whatsoever. And previously she seemed able to socialise after work with no thought to childcare. I'm sure there've been times in the past when he's turned up at the ED.
Mind, I don't know why I expect logic from Casualty/Holby...