I too have close family members with dyslexia. If they asked whether they'd make good programmers, I'd honestly tell them that their disability would make it very challenging and frustrating. They could still do it, but their passion would have to be enough to drive them to work much harder than their colleagues to achieve the same results.

I'd also recommend that they go to whatever lengths necessary to eliminate typos in their resume because it's a prime opportunity to demonstrate that they can achieve exacting precision when necessary.

That being said, they are all happy in careers where character-for-character precision is not as important.

Re: typos in resumes, I'm less strict than I used to be and try to focus more on work experience or other real world metrics than using typos as a proxy for programming productivity.