Also If I am sole owner and decide to add my adult child , can I also decide to remove her?
Yes, you can add your child to your house.
No, once you have added her, you cannot remove her unless she agrees.
You will also need to file a gift tax return for the value of 1/2 of the house if you put her on it. You won't have to pay any actual tax unless you are over your lifetime exclusion for gifting (million plus) but you will have to file the return.
Also, it would likely be better for your daughter to inherit the house rather than you putting her name on it, unless she would plan to live there. If she inherits the home she gets a stepped up basis and therefore won't pay any capital gains tax on the proceeds if she sells it right away. If you put her name on it ahead of time, she gets your basis, and therefore will have to pay capital gains tax on some of the money.
All in all, you really are not doing your daughter any favor by putting her on the house, again, unless she would plan to live there.