Any combination of keyboard characters may be a password. The more obscure and longer the character combination is the 'stronger' the password would be.
Your best option if your friend forgor her password is to contact the website for assistance. There may be a reset password utility on their site somewhere. Nobody here can give you someone else's...
In general, no. Passwords are usually encrypted, and the login process doesn't actually check the entered password against a stored value... they check to make sure that what was entered encrypts to...