How can I help my sister find a good man?

I managed to find my oldest sister a good man last year. My sisters boyfriend was a work friend of mine and he was the only decent guy there.

My middle sister Katie is very complicated and difficult to deal with without sounding to harsh. she's never had a boyfriend and now me and my older sister both have boyfriends she's always left behind.

she's very pretty and fun to be with, if she's in a good mood. My sister is on autistic spectrum and sometimes can be extremely difficult to understand as she's awkward person. She can be very sweet at times but i think my mum has treated her like a baby slightly and she's to comfortable relying on my mum to be her companion.

she's not good with talking to people and is grumpy a lot of the time. She talks to boys on the Internet and at work and has tried tinder but she's had no success and kinda leads on theses boys who do talk to her and no offence but there not the type of guys id want my sister dating.

Theirs this 36 year old Brazilian man at her work whose also autistic who keeps orbiting her. My sister is only 24 years old and he's very controlling and obsessive with her and won't take no for answer, he keeps buying her gifts and making her food and telling her how pretty she is. No one in the family approves, but my mum is to tolerant about their relationship and this letting her lead him on because she enjoys the attention and just says there friends.

Sorry but male "friends" don't ask you out constantly and tell you, your pretty and get upset when talking to other boys. We even saw him today whilst going shops and she asked me if she was looking cute and went red in the face. All the men at her work hit on her from the sounds of it and are very sleazy but she just enjoys all the attention.

there's nice boy on tinder she's been talking to but whenever he asks to meet she says no to him I've Facebook stalked him and id much more approve of that guy rather than the guys she is paying attention to.
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he keeps saying she doesn't want a boyfriend but we all know it to be a lie or she would not be acting the way she is lately and would have never signed up to tinder. Its just im so scared for her. I don't want her to have a life outside of my mums smothering, i don't want her to be living at home her whole life feeling lonely but at the same time she's very sensitive and this guy would need to be very understanding, kind hearted towards her and have a lot of patience
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when it comes to certain things. She hates being touched by others and acts viciously when anyone but mum trys to hug her.

Im very good at setting people up and I've tried so much to help before but honestly all the guys on offer are not good enough for her. She needs someone whose gonna push her to get out there but also be gentle with her, have a good sense of humour and be laid back and the one we all approve of she keeps rejecting.

She likes bad boys but i can just see her getting hurt
How can I help my sister find a good man?
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