Did they set these up themselves or did they have an attorney or some other professional help them?

If they had a professional - I would expect there to be an LLC formation document along with the certificate of organization, and a lot of times an LLC Operating Agreement as well which spells out the answers to some of your questions.

Yes - LLC's with more than one member do have to file either a 1065 or 1120-S depending on which is elected.

Not sure that it is 100% correct but you may be able to convince your self that taking her total #'s for the year and prorating them based on # days before and after funding the LLC does not distort income.

Which brings up another question - Did they in fact ever "fund' the LLC's - IE Legally transfer the properties into the LLC's?