Took my eldest out for our first ride together today, only 5 miles but she loved it. However she said her butt hurt and I think she could benefit from some padded liners.

Any recommendations?

I’ve got my kids some of these:

https://www.polaris-bikewear.co.uk/Terra-Childrens-Cycling-Shorts-p/pol01-5727-p.htm

Word of warning about the sizing though – my 8 year old is 140cm tall and the size S still fit him. My 4 (almost) year old is 115cm and I’ve just got him a pair in S and they’re quite baggy.

Decathlon ones did ok for my two

Dare2be also do some which iirc i got from Evans.

James

Decathlon or Polaris were great.
The Altura ones – we had two pairs that needed sharp edges and sewing in the pad sorting.