I once visited my aunt who was living in a senior apartment and I saw an absentee ballot sitting on her coffee table. I asked her if she had asked for it and she said no. I then asked her if she wanted to vote. She said yes. I helped her to fill it out by reading out the names of the people running for office and asking her the questions for the propositions. My aunt had macular degeneration and could not read the form easily. I then took her ballot to the correct voting authority.
You did the right thing. You were a close relative. In Pennsylvania, if you assist someone in person, we have an additional step of signing an assisted voter register and an election worker is to witness that there is no coercion or undue suggestion involved.