A "couple" could explain two cars. They may have driven there separately after work. And they could have been legit (as I theorized before) and this had nothing to do with a "fake" showing.
Seems like about an hour and a half apart would be quite a distance for most to drive in separate cars to the same destination probably?
But I could see someone having said it was going to be a couple, then one showing up alone, to sort of catch her off guard.
Say like if the first arrived and said, "Oh my ____ (spouse/partner/friend/whatever) had to make a stop on the way over for ___ (a drink? gas? whatever). They'll be right here. Let's start looking through the house. They'll be right here." Or something along that line.
Then Bev could have been in the house with one, and if the other came in (especially if with a weapon) it'd be very easy for two to take her down, especially if she's got her guard down with a friendly client and they're chatting slowly going through the house, and she's expecting the other to be just as 'normal,' only to have someone essentially then corner her.
And it'd be really easy if a female arrived first because in most cases, that'd cause another female to let her guard down even more. Out numbered, cornered, one with a weapon, or all of those together could really have her in a bind with few options. Especially if a second person came up from behind and overpowered her so she couldn't try to use her phone.