Solution

25830

First name
Tallulah Stephens
School
Salcombe Preparatory School
Country
Age
8

The answers to the code are as follows:

pat-a-cake
the-west-wind-blows
you-are-working-hard

my codes are as follows:

dl-rl-yba is go-to-bed
txpe-vlro-exkap is wash-your-hands

Different codes I've made up could be:

go forward 3 letters so A=D, B=E
or
go back 1 letter so A=Z, B=A
or
go forward 1 letter so A=B, B=C