Ofsted Variation - Is anyone able to offer advice

[Petal291]

Hi all, hoping someone might be able to give a bit of advice on this one.
I currently look after a little girl, she is 4, from 12 - 15:30 daily. Mum gave me notice a couple of weeks back as she was moving with her job at the end of February, i won't go into their private circumstances. Anyway i have already signed contracts for a toddler to start full time with me in May.
Mum of part time little girl told me on Friday, that for one reason or another, her new job will not be starting now until July this year and can I keep her little girl as usual until the end of July. I have explained to mum that i've now signed contracts with a new baby starting in May, which of course she is upset about but understands she gave me notice.
I have now been told about applying for a variation for existing children for continuity of care. Will this situation work???
Not mum's fault that the new job isn't starting now until July and not my fault that I signed a new contract to start in May.
I would need the variation only for 3 months...
I would need to apply for variation ASAP as if it was declined mum would need to look for new childcare.
Will ofsted want parents details etc....how does the variation work??
Any advice would be great.
Thank you.