My Dad's dead now ,but when he was alive he was 'Dad and my Mum is always called Mam
My Kids are grown up now ,but my oldest and youngest always say ,Mum ,middle Son calls me Mam and the youngest Son calls me either Mum or Mother/Muvva

Neither of my parents are still alive. When I was growing up it was always Mum and Dad but in latter years I called them by nicknames of their first names. Not sure how that came about.

One thing I always found rather weird about my parents years ago was when they called their respective parental in-laws (my grandparents) mum and dad occasionally too. You should not call your in-laws the same as your real parents although I believe it used to be quite commonly done. You only have ONE mum and dad.

my kids call me mum or ma, my youngest often calls me by my christian name because he thinks it`s funny but he`s ginger so...

my kids call their parents mum[my] and dad[dy] or mumma and dadda [flat vowels].