Do Pregnant Spiders Maintain Two Webs?

[earthpigg]

Hi,

I have spiders in my back yard. Brown and black. They don't mess with me, I don't mess with them. They set up webs near the area I walk and keep the stinging insects - dudes that have messed with me without me intentionally provoking them - away from that area. (We have a vast array of bees - and stinging critters that eat bees - but my spider friends keep them on the other side of the yard.)

There's a pregnant one, and it seems to move between two distinct spider webs. Observations:

-I don't ever see spiders at both webs at once. Spider present at neither, at one, or at the other, but not both.
-She looks to be pregnant. Either that, or she is more well fed than any of the other spiders I've seen back there. Or, there are two pregnant spiders that somehow coincidentally are never around at the same time.
-Wrapped prey is present in both webs.

So, is it normal for a spider to set up and maintain two webs?

I live in the San Francisco Bay Area, Marin County to be specific, if anyone is curious or especially knowledgeable about arachnids.

EDIT: My friends don't look exactly like anything here, but look closest to this. She's got some white markings on her back.

[thatguruguy]

She took her baby daddy's web in the settlement.

[dniMretsaM]

She took her baby daddy's web in the settlement.

I suppose that's theoretically possible as some females kill/eat the male after mating.

[Linuxratty]

I suppose that's theoretically possible as some females kill/eat the male after mating.

Never saw one maintain two webs...They lay eggs so they don't get pregnant...Hang around and you will see a delicate egg sack eventually. The little ones hanging about are the lunches..I mean males.