Hi Lola's Mummy,
DD is 8 months and currently has:-
Longish breastfeed 7am-8am
Midmorning snack short breastfeed 11am (sometimes misses this, if she doesn't ask for it, I don't give it)
Mid afternoon snack short breastfeed 3pm
Longish Bedtime breastfeed 6.45pm
She also gets 3 x solid meals and puddings in between these times.
I expect she'll fully drop the midmorning snack feed by 10 months and replace that with a solids snack like a ricecake or some fruit.
I would expect if I was going back to work when she was 10 months, that I would need to express around 7-8oz for 1 x midafternoon feed - 1 for each day that I was at work.
So if I was you, I think I'd express around 21-24oz a week for the three midafternoon snack feeds plus a little extra milk just in case, so it might be an idea to start building up a supply for the freezer fairly soon.
The way I get the 7-8oz amount is that I left DD for the afternoon the other day and she took that amount of EBM from a bottle - I'm fairly sure she doesn't take this much from me at that time of day as she is only on for about 3 mins in the afternoon but I wanted to make sure she had enough and she gulped it all down! Obviously I really don't know how much she has but I'd rather make sure there's more than she needs. However it took me about 4 expressing sessions to get off that amount of milk so unless you've a brilliant supply (mine has dwindled so much since weaning), I would definitely start to build up your freezer stock soon.
Hope that helps.
Valentine Xxx