Wrap Around (school) Care

I am a single mum who is a teacher. My children are ages 5 (girl) and 2 (boy). I need help getting them to nursery/school in the mornings and collecting at least my daughter from school every day and sometimes my son. We live right by Kew Bridge station and they both go to school/nursery by Ravenscourt Park as I work at a school in Hammersmith.
Duties would include prepping my daughter's snack, helping getting them dressed and ready to leave, joining with us on the commute and then taking my daughter on to school after dropping off my son.
In the evenings, she would need to be collected from school, brought to the playground or to a playdate or to an afterschool club, then coming home and making dinner for the children as well as prepping my dinner. We need support with homework as well as light housework related to the children. There will be a few nights each month where I would need help with the whole evening routine as I will be at work later than usual. I would also look for the occasional later weekday or weekend evening so I can either attend a work event or spend time with my partner. There is the opportunity for ad hoc weekend hours to allow me to attend a personal appointment, and I'm hoping to make a relationship with someone who is able to very occasionally stay overnight with the children so I can either go on tour with one of my school choirs or do an overnight with my partner.

My kids love to play and have big imaginations. I am looking for someone experienced and established in London who is kind but firm and willing to play with my kids as well as support their developmental milestones. I need someone reliable as I am on my own here and have no family around to support me.