Good luck with the mum who can do mondays, rhubarb.
IME it is so difficult to ask for a regular commitment from other parents at school. I really feel for you as I have consistently had this problem. A one off is fine, but to ask someone to commit for more is really difficult - and then to work out how you will pay them or reciprocate with a favour. And IME if you ask, people often find ways of saying 'no'
Parents IME are not very perceptive about childcare problems such as this. At our primary school, (a small, village-like school on the outskirts of London) most parents either don't work at school pick up times or have family living nearby to collect their offspring. Most simply cannot get their heads round the idea that some parents who work full time just don't have an available grandparent/aunt etc who can step in with childcare.What's mroe, they have no idea of the harsh financial implicationgs of covering what can be just a 10 minute gap in your childcare arrangements. We have no family to help, never had, and we are in a minority.
For the last two years a lovely parent, who is now a friend, has been collecting my ds2 from school and dropping him at playclub. Luckily she lived round the corner from the playclub. I paid her a small wage for the commitment and 10 mins extra time a day. But her son has now left the school and so I had to find another way of getting ds2 to playclub 5 days a week. The school and church advertised for an escort (escorting up to 5 children from the school to the playclub). No one came forward.
I then got together with two other mothers (both close friends with each other) from school who have children at the playclub and suggested we try a rota system if all else failed, each collecting all the children on different days. I did this while putting pressure on the council to supply a playworker to escort the children.
Imagine my reaction when I phoned them during teh school holidays to be told in a casual way by one of them, that they had sorted out a rota system between the two of them! Leaving me in the lurch a week before term began.
This is why I decided to let my ds1 do the after school walk with ds2. It is not a perfect solution as it means ds1 cannot stay late at his secondary school, go to homework club or extra curricular activities. I very nearly had words with the two parents - who hadn't even the courtesy to let me know of their private arrangement till I phoned up and asked them!
Luckily I didn't, as two days ago one of the parents phoned me and asked me if I would like them to pick up my ds2, as they had space in their car. I think they had seem my ds1 collecting ds2 from school and (I hope) felt guilty.
Sorry about the rant, but after school playclub provision is a subject close to my heart at the moment.