Help explaining this Inspector Calls quote.

Be more definite and don't say 'maybe'.

Loool I don't think they need it now, they may have a family even right now, loool.But this is helping me so thanksssss, I've looked for so long.

I know I am 10 years too late.. But when Sheila says "You mustn’t try to build up a wall between us and that girl. If you do the inspector will just break it down", she is using a metaphorical wall that the Inspector will knock down to show he insightful understanding of his methods. She knows that if they try to keep anything from the Inspector, it will only make things worse. The other characters do not notice this as quickly as Sheila does. She breaks down this metaphorical wall that her mother first put up, between the working class and middle/upper class. This shows that she has adopted the Inspectors and Priestley's socialist views, therefore she shows social responsibility - one of the main themes in 'An Inspector Calls'. Priestley uses Sheila, as well as Eric to show his opinions on youth. He felt that there was hope in the young people of post-war Britain. He saw them as the ones who would help solve the problems the country has with class, gender and social responsibility. This is also seen in how Sheila is deeply affected by Eva Smith's death, she accepts responsibility straight away and promises to never behave in such a way again. This is not the case with the older generation, Mr and Mrs Birling and even Gerald do not accept responsibility and we do not get the impression that they will change. This is surprising, since we would typically imagine the older generation to be the ones to accept responsibility, however it is actually the younger generation that do.
Hope this helps someone (: