Its quite complicated.
My neice and I were pregnant at the same time. She was having her third, I was having my first. My mums middle name is also my neices middle name (my sister named after our mum IYSWIM)
Whilst pregnant she made it clear that this was 'her' name and she was going to give it her dc3 if she was a girlas a middle name (she had two boys so wasnt able to use it before)
DH and I couldnt find a name we liked as much as this and I also felt as it was my mums middle name that I wanted to use it so we named our dd it as a first name which my neice wasnt best pleased with although she did still give it to her dd1 as a middle name.
Fast forward two years later and I am pregnant with DC2 and the only boys name we like is also the name of my neices stepson. We hardly see my neice but would it be wrong to use this name?