Don't know what Sam will opt to do, but Wendy is opting to stay still (since so far they are going unnoticed) until the woman gets in the car and starts to leave, and then hopes to follow her whereever she's going.

She will be noting the car's make, model, and license# in case they lose the car later.

Logic in her mind is that this is likely a newly assimilated maurezhi, and she might be returning to their hive.