Sale of home owned as Tenancy in Common - One co-owner selling their share to the other

Two co-owners (A,B) in a tenancy in common ownership, principal residence for both individuals.  Lived together in the house for the past 2.5 years.  

Co-Owner A buying Co-Owner B's interest in the property, quit claim to be filed with the county

Co-Owner B selling their share, gains on the sale are < $250,000.

Does Co-Owner A need to file any forms for tax purposes (ie. 1099S?)

Are there any tax implications to Co-owner B given that it was their principal residence and gains are < $250,000 (total sale price-amount invested significantly less than that amount)?  Does any paperwork need to be filed?

Any suggestions as far as talking to an accountant?  Have already spoke with one and says nothing needs to be done, but doesn't hurt to get a second opinion given the potential implications