I'm guessing she wanted to double back to make sure she really saw a child? Just a guess.
Google Maps is telling me from Taziki's to her parent's neighborhood (I don't know the exact address but MSM published the photo of the sign leading into it) is 6.4 miles, or a 12 min drive if she took 459. There are back roads but probably a lot of lights, so let's say she was indeed on 459 initially to get to the Lake Wilborn area.
The area her car was located in appears to be about halfway home, so let's say it took her 6 min to get from Taziki's to mile marker 11-ish, spotting the supposed toddler as she was zooming by.
She gets off that next exit, backtracks to the Rt 459 and Rt 31 intersection, and gets back on 459 south.
Let's say that leg of the trip took another 6 minutes. Now we're at 12 minutes.
And now another 4 minutes or so to get back to mile marker 11. That's about 16 minutes which would be 9:16 if she left Taziki's at 9:00 on the dot, so I think it's doable.
Of course there would be lights and some traffic, so the time could actually have been 20 minutes or 25 minutes, placing her at the location for the second time around 9:20 or 9:25, and we know her flashing hazards appeared on the Gray Hughes video around 9:31:33.
I think she could have left Taziki's at or around 9pm and doubled back to the location(s) by 9:31.