i Register
In some senses, chairwoman is marked as obsolete. Watch for register when choosing this word.
noun
A female chairperson
1845, The New Statistical Account of Scotland At a Reform dinner which took place in 1832, the united ages of three women, including the chairwoman, amounted to 264.
A charwoman
[…]according to her skill and qualifications, whether in the nature of a dairy-maid, a cook, or chairwoman.