I don't have a huge amount of experience with single moms (I've bedded a few of them here and here over the years... but not my usual type), but from what experience I do have, plus what I hear from friends and others, it seems like you will run into three sorts:
Horny and lonely. She'll jump your bones the first chance she gets. Doesn't sound like this is your girl.
Conservative, searching for a boyfriend. She'll slow things down if she can, but once she knows she likes you, she'll be yours. Probably won't meet her kids until long after the two of you start to date.
In search of a replacement father for her children. She'll let you meet the kids and try to get you bonded to them before she ever moves things to sex. The most important metric for her is "Will this man be a good father to my children?"
If she's #2, maybe that's okay. I'm not sure how long it normally takes you to bed a girl, and how far outside your usual league this girl is. If you have to pursue her for more than a month without bedding her though, even if you're not very active at meeting new women, I'd hope she's world class (or even, preferably, wife material).
If she's #3, I'd probably cut bait, unless you have an overly strong urge to be a father and don't much care whether it's your kids or another guy's. There legitimately are men like that out there, and if she's a #3, odds are she wants one of them.
Whether she's a #2 or a #3, sounds like you're deep into boyfriend territory. So you should probably only proceed if you're confident you want this girl as your girlfriend.
Otherwise, meet some new girls who won't stretch things out for months.