She taught from behind a veil and she was a special case cause she was one of the most authentic treasure trove of Hadiths, having lived with the Prophet(pbuh) most of her life. That kind of knowledge that was more valuable than all the riches of this world had to be passed down and hence was a special case. Aisha( RA) was wrong to lead the battle of Jamal, read up on the haidth of the fountain of hob, she realised it at the fountain of Hob and used to cry all her life for leading the battle against Ali(RA). Please dont reference Islamic history out of context, the primary role of women in Islam is upbringing of children and taking care of the family unit which is the most important job one can have.