I expect she'll be like all Mum's and get on with it...
She knows a thing or two at 57 and will probably plan help carefully to avoid too much stress. At that age she may have worked and be nearing retirement so she could have enough money to cope comfortably. She must also be very fit but will probably take longer to get over the Caesarian than a younger Mum..
There will be problems later as the child grows up with an 'old Mum' but then I was too, at 39, and and having a surprise baby then was the best thing ever.
We're off shopping for clothes tomorrow but will the older Mum want to do that when her daughter is 20?
I'm sure she'll be a really loving and laid-back Mum and I wish her all the best for the next few years.