If your sw is being unprofessional then that is a very different matter. There is never an excuse for that. Can you say what exactly is happening that you feel you are having to "give into things" which make you feel uncomfortable. Do you mind saying what age your child is? When you say "talks" how many has she done. If I am feeling positive about the applicants and the way they interact with their children, this tells you an awful lot about their style of parenting. If children of say under 7 were birthchildren I would usually just talk to them generally in the company of their parents.
With an older child (say between 7 and 12) I would take some drawing paper, felt pens, and get them talking a bit about their family while they are drawing. You can tell a lot even by asking them to draw their family (stick people) and other important people in their life. If children are closer to mom than dad, then dad may be drawn a little but apart, not always, but things like this are helpful and it also means you are not sitting looking at a child and asking questions. I would draw alongside them, just this and that, so it is a joint thing. I would ask them if their mom and dad had told them about a foster child, and they usually say yes, and then I might ask how they would feel if the foster child broke up their lego or whatever it is they are into, and they usually say, they'd build it up again, though one child aged about 7 said that he would "trample on their toys!" Fair enough really for a 7 year old.
If I was happy after this I would only see the children once, and if the parents were realistic about fostered children and the difficult behaviour they may have, I would leave it to them to know their children well enough to go ahead (or not) as the case may be.
SO how man "talks" is this sw having with your child.