Big sister / companionship for 12 year old girl

We are looking for casual babysitter for my 12 year old daughter during the Dec/Jan school holidays (and after school next year if possible). It is actually more like companionship / big sister work. Pippa is in Year 6 and is autistic and has ADHD. She goes to a normal school but needs extra help with schoolwork, and struggles a lot with friendships. At the moment we are looking for a 1-2 days per week during the school holidays (I work full time), you would be doing things like going to the park, baking, going to the shops, going for a swim. Please apply if you can help!