I know there is a reference somewhere that says if your wife or a friend says you look bad with your sefirah beard, you can shave it. I just don’t know exactly where to find it.
With regards to the Halachos of mourning for a relative, there is such a halachah, that after the period of Aveilus is over one may take a haircut when people point out that one’s hair is too long. However we are unaware of such a reference with regard to the prohibiton of taking a haircut or shave during the Sefira. If you come across it please let us know.