Web browser email versus client email

My wife wants to set up a different email account for her laptop than our
desktop. I am wavering between using one of the freebie web based email
accounts: Hotmail, Yahoo mail, Google mail; and between something that
supports using the mail client that came with Vista. She likes being able
to do the Send/Receive and work offline although, with wireless in the
home I don't know how often that will be necessary. She's going back to
college starting today, and, may take the laptop to some scrapbooking
events.

I am assuming that the web based ones probably don't have the ability to
interface with that mail client because then it would be hard to subsidize
the free part, eh? Am I wrong? If so, how do I set it up?

I am checking with our ISP to see how much it would cost, if anything, to
add an additional email account.

Any pro's/con's I should be concerned with regarding either client?

Rob Berendt