A mum has explained why she let her 15-year-old daughter get a tattoo.

US author and speaker Diana Register wrote about her daughter's decision, saying the fact the tattoo means something important to her makes all the difference.

She says that although she wasn't sure about it at first, she was eventually won over as her daughter Kaitlyn's choice of tattoo was a tribute to her dad, who tragically passed away from cancer when she was just 13.