Ну и досталось же ему от моей сестры!
They are talking about a ladykiller trying to seduce a girl.
I can't make head nor tail of the meaning of this sentence. I wonder if "dative + достаться + от" makes up a set expression?
Достаться + object in Dative means
to be received by (usually in the context of distribution among a group of people) or
to accrue to, e.g.
In the idiom, with the addition of preposition
Нашему атлету досталась бронзовая медаль - A bronze medal was received by our athlete
от, it means being on the receiving end of someone else's rage or violence.
This is again an impersonal construction, that which is received is only implied.
ну и here is an intensifying cluster expressing enthusiasm, cheer and a kind of post factum encouragement.
In this case "досталось" is a short form of an idiom "достаться на орехи" - "got punished / got scolded" depending on the context. The referred punishment is not too harsh, but palpable.
Assuming that the main character was verbally abused, the phrase can be interpreted as:
Ну и досталось же ему от моей сестры! - Well, he got totally scolded by my sister!
The other forms of the idiom are: