I hope
"Being dumped on by a friend" = being invited and then uninvited.
"Getting a weekend away out of it" = someone is whisking her away so she doesn't get upset while the whole wedding she was uninvited to happens.
Alternatively maybe she has been asked to decorate and has very quickly booked a weekend break that clashes to make herself deliberately unavailable.
Can you ask on fb "ooo where you off to? Anywhere nice?"
Might tell you if she is heading towards or away from the wedding...