nanny salary if she has her own children

I think that's far to high - I agree with £8/net, especially since she'll have 2 children with yours in the holidays.
She can't have the children at her house without being a registered childminder.

TBH - You could easily get someone cheaper and as qualified without their own children too. I'd look again.

Logistics - 4 children all needing carseats. Got a big car?

Her DS1 will be at school but only for 6 hours, possibly less/more. Your children will have to take her DS1 to school, even on days when you would rather they didn't... Snow, kids feeling unwell. Your children do not need to be up in the morning, they don't have to be dressed by say 8:15am, where as with her having to take her DS1 to school, your children will need to be up, dressed and ready to leave the house.

That is why salary for a nwoc is lower, some benefits of having a nanny are eroded as the nannies own child does get priority at times, such as getting that child to school on time.

£12-£13 gross seems a bit high for shared care. I would try to get that down 30% or so, as with the additional costs you will have as the employer it is going to be higher than you would be paying a childminder I would have thought. Are you needing hours of care which a childminder would not do?

The two days in their home (as a childminder, so they dictate the cost and you pay them the fee) and 2 days at your home (where you pay them but deduct tax, ni and pay employers ni plus all expenses for outings) I do not feel is good. Muddy water comes to mind... are they a childminder, are they a nanny, can you tell them what to do. 2 days you can tell them what to do, 2 days you can't.

Why do they want to do 2 days at their home? I feel they either need to be a childminder, or a nanny, not both for same family. Fine if different families but in your case it makes for very muddy water for you to both swim through. Two different relationships with the same person, it's going to be a challenge.

Will she be doing the school run for her child or is someone else minding him before and after school?

That's a cheeky ask for someone a) bringing her own children and b) actually childminding, not nannying two days pw.

Are you sure you want a nanny woc 3 days and a childminder 2 days?

... and even if you are, you'd be a bit of a mug to pay £10nph for it IMO.

Just reread and see that she has experience as a childminder so it could be that her registration is still active.

£10 net per hour is the sort of wage that a nanny with 8+ years experience would be looking for (without children to bring). So definitely less if she is bringing 2 children with her.

Also, if she is planning on having your children at her own house she MUST register as a childminder for those days.

I doubt the looking after at her house works as a nanny but you would need to check - I thought she would have to register as a childminder. But no way would I pay that wage for someone with 2 of their own kids.

Yes a nwoc should earn less. Average is 20% less so £8 nett but discuss gross so maybe £10gross

Very lucky to take 2 kids with her - so maybe I would do 25/30 less