I may have posted this before but this is my theori regarding his family.
Not too long after Tyldak's death Kahvi met, and recognized, Teir's father.
Because Kahvi didn't want the child she stayed around only for Teir to be born and be weaned before she quickly left. We know that she's not generally a bad mother; her treatment of Venka during KoBW seems - at least to me - quite motherly, and losing Vaya was one of the few things that ever made her cry.
When Teir was still very young (a few years at the most) Teir's father met the woman Teir would eventually come to regard as his "mother" and had a child with her: Teir's brother. This would also explain's why Teir's father said that "It's easier when Heart meets Heart." I think Teir honestly believed that his 'adoptive mother', so to speak, was his mother; he'd forgotten everything about Kahvi and only remembered when smelling that braid.
I know that Teir's "mother" and (half-)brother eventually left as well, but two things:
1: The saying of "It's easier when Heart meets Heart." may have orginated before that happened.
2: Even though they eventually left is still was easier.