Yeah, I had thought about that after I saw the eggsacks. I have actually had some really small widows that wouldn't grow at all and my smallest one is the only one that produced an eggsack for me. Mine were all black once adults though, the L. hesperus I've seen in the brown phase around here are all really tiny, they're beautiful though!
I thought the cobweb spider looked the most like your pictures judging by the dorsal pattern, they're from the same family that the widow is in, if you want to do more looking I would keep it in that family since they would have the that same body shape.
By the way, the family is Theridiidae, good luck!