Also... yes, you're completely right that service users won't differentiate between 'professionals' visiting in the same way you are i.e. One terrible person and the others are great.
The one terrible person being able to behave in this awful way to vulnerable people, won't be regarded as a one off. The way it seems her behaviour is accepted by the other professionals will mean that from the service users perspective, any and every person from that professional body may also behave in the disrespectful and unprofessional way she does. Which is a scary thought from someone who has to have these visits and has no power in this type of relationship.
You (& others) visiting with this unprofessional person, and doing nothing to stop her behaving in this way, will also be strengthening the sense that her behaviour is endorsed by the other professionals around her.
It puts you in a really tricky position, and I'm not sure you can do much about it from the service users perspective, except perhaps refusing to work with her? And of course complaining again with a list of clear factual examples, pointing out the impact of this on service users. Both directly and also the potential impact on their relationship with whatever 'service' you provide.
Sadly, one bad persons behaviour isn't mitigated or erased by one good persons behaviour. Someone behaving unprofessionally and nastily will be leaving marks on the vulnerable people she's being allowed to be awful to.
E.g. As a physically disabled person, I was forced to go through a 'reenablement' program as it's the only entry point to adult social care in my area. It's designed to re-enable elderly people coming out of hospital and help them re-establish their independence. Certainly not designed for an adult who can't physically do something and will never be 're-enabled' no matter how much a carer forces me to do it or shouts at me, or tells me I'm faking, or laughs at my attempts to do things I can't do etc etc etc.
There was one excellent carer, and a couple of carers who were fine, but they didn't balance out the abuse I suffered at the hands of other carers who were apparently just 'exceptions' and the 'odd bad egg'. It's their abuse that I'm still battling to overcome years later, being left traumatized and terrified of ever, ever, letting any carer near me in those ways again.
The good carer being good doesn't out weigh the cruelty and hurt of the others. Once someone's pointed and laughed at your fucked up body, whilst you are naked and dependent on them to give you a towel (which they won't give of course, too much fun laughing at my naked body)... well, it doesn't matter how professional the next person is does it?
At least I could fight against this but anyone who's more vulnerable due to sn or not being able to communicate etc. the abuse carried on for 6 weeks before I could get it stopped. Imagine if it just carried on and on...
Just trying to illustrate how different the perspective of a ss team / carer team / etc will be from the perspective of the people this woman is damaging on the ground.