This must be the most unique FML in the history of the site. Good on ya for taking care of the little Sheila!
Hand-raising an animal--especially one that generally is wild is never easy, but it will definitely be a memorable experience and totally worth it.
Peeing on someone is the universal signal for "feed me..."
What are you doing hand-rearing a wallaby in the UK?
Either she's helping to raise it for a zoo, or she wanted a baby via immaculate conception, but God has a twisted sense of humor.