She might be better off with a reseller account of some sort if there's going to be lots of domains.

Nethosted do some, cheapest

nethosted get my vote ,very helpful support .

For business critical applications, I'd always suggest staying clear of shared hosting. Personally, I don't like to put client's and my own business websites at the mercy of someone else testing flaky scripts or leaving the server open to hackers.

So, I guess it depends on requirements then.