I don't think she was wicked. She didn't take any money for the 'service' she provided and I think she genuinely just wanted to help these young girls who'd made a mistake. It's hard to imagine (or remember if you're old enough) how things were in the fifties - no going along to a clinic and having an abortion on demand. It was an absolute disgrace in those days for a single girl to become pregnant bringing shame on the family.
Incidentally, i don't remember Imelda Staunton being in Mrs. Henderson Presents - are you confusing her with Judi Dench?
It's such a brilliant film, not a bad performance from any of the cast, but what I find so awful about the situation, back then, was the rules were made by men, upheld by men, acted out by men but it was always the women that suffered. Ok, I'll get off my feminist soap box....
And in answer to your question (sorry, forgot!) no I don't think she was wicked. She genuinely wanted to help the girls. She'd been in their situation, and so offered them the same solution that she has used. But the 'go between' (can't remember her name), she was! She gave Vera none of the fee, and then sold her sugar, sweets etc. What a cow!