Don't quote me on this, but I think that's a 2 month milestone, so your little one would still be in the realm of normal for not doing this yet. If you're concerned though, check w/ your local health department. They have great screening and early intervention programs.
Personally, I'd give it a little more time before becoming too concerned. Certainly if she's not doing this w/in a few weeks, I'd probably check with doc. But keep in mind there's a huge range of acceptable when it comes to meeting milestones.
GL!
