Some of them have been ordered to give the correct answer " they're normal ". Some of them just feel under pressure to give the correct answer, because they love the child and want them in a permanent placement . Or dislike them and want them to move on.
So you need to catch them with their guard down, when they think you are talking about something only indirectly related to the child concerned .
So I wouldn't ask closed questions , or you get
Is he a good eater ? Yes he's totally normal
What does he like for breaksfast ? Toast
You want to get them to talk . Depending on how chatty they are m you might need to ask your " rice crispier or cornflakes " questions first. But even if he lives off toast for every meal, she's not going to tell you that anyway.
So I'd say stuff like
Oh gosh, we are a bit nervous, this is the first item we've done this and I'm not sure what to ask.where should we start ?
Jane his SW tells me that he's made great progress since he came to you . What was he like when he came ?
How nice for him that you / your neighbours /sister have a cat / budgie.
It will be hard from him to move away from all his school friends /kids in the street / football club.
These may seem random but they are probing for information about his past ( BF and former Fc placements if applicable ) . You really want to find out discreetly why he moved from another FC and why he's not with any of the BF. FC will be more honest than SW.
You are also looking for red flags - like cruelty to animals and smaller children / babies, issues around food and elimination , behavioural problems, indiscriminate affection
You need to ask as inexperienced people seeking her advice and not as an examiner looking for the right answer.