To get back on the original title of this forum. Some nannies do get multiple offers, some don't.
I know as a Professional Nanny of 25 years, that I have most of the time, interviewed with one family and known by the time I left the interview, whether or not I would take the job if offered and even if I felt I would be offered the job. I have also known by an interview that it would not work.
Every nanny is willing to do different things, some are willing to do housework, some are not. I did in the beginning but now I dont, other then anything to do with the children and then if they are old enough, they help with chores. Some have a formal college education and some dont. I have experience and some professional nanny workshops/conferences and belong to a great nanny group that also has these great educational opportunities we can attend or are brought to us.
Some families want the more formally educated and again some want the actual hands on years on the job kind of nanny.