I say it all the time and I am a SOMALIAN XD and no other fellow SOMALIANS XD (including family and friends) have any problem with it. It is highly unlikely I will ever meet your friend so I don't really care what she thinks.
I also call my Belgian friend 'Belgish' and I do call one of my friends 'Germanian' too funnily enough. Why do you even care what I say? I really don't have the time or patience to have this argument. It's so petty. Asalamu Alaikum.