I'm a petite single mom to an 8 year old girl. In other words, we'd be a REALLY easy target. Well, until DD opened her mouth. When they figured out that she n.e.v.e.r shuts up, I'm sure they'd stop the kidnapping

... I have walked home (well, to our hotel) at closing multiple times, both with and without DD, and only once or twice felt slightly uncomfortable with the walk. We stay at the Super 8 on Katella, right off Harbor, so it's about 15 minutes away.
It's a relatively well lit, well populated area. It's rare that I have been "alone" on my walk to/from the park, because there are usually other groups around... I just walk a little quicker to "catch up" with them if I'm really feeling freaked out--close enough to look like I'm "with" them, but not so close that a kid from the group asks me who I am
That being said, a mile away is a ways to walk after a day at DLR, and I would definitely start considering an ART pass at that point. The Katella/Harbor intersection is about as far as I am willing to walk, because on the way back, every step I'm thinking, "Are we there yet??"