Vocal stimming qu-when does it become a stim?

Hi all

My daughter is 5 and waiting for a private diagnosis.

She fits a potential PDA profile but not 100% sure.

She has started making a clicking sound over the last months and has always been a singer and dancer. Even at the age of 1 and half 2 she would sing and do sing and sign and dance.

My qu is how often does a child sing or repeate singing and dancing for it to be considered a stim? She has episodes.of singing a lot during the day but my family say she just likes to sing and dance...some kids just like to.sing.

Today she did a repetitive dance and song in the shower for over 7 mins. The same dance and song that she had seen. I feel that 7 mins repeating the same dance and song isn't usual but have no idea.

Guess I'm not sure.if I'm over thinking it as singing can be very usual for some children with and without autism.

Really wasn't sure when it becomes identified as a 'stim'.

She makes clicking sounds randomly but sings when colouring, dancing, playing, drawing or walking around the shops. We know when shes very content as she sings continuously. Doesn't sing when she's angry or upset 

She doesn't do it at school but does sing around family but not exessive but.mostly when at home.  This has increased during the summer holidays. Sometimes.she will.sing songs she knows and other times.its just saying words but with a tune to them and she will also make up songs.

Each day is different and it's.not impacting on life negativity but curious if this could be a stim. She sings at home everyday some days more than others

Thanks