Confused about how much milk 8 month old should have

[littleanimal]

DD is totally bf as she has always refused bottles (I've tried everything!)However I am going back to work in a few months. I've persisted with a tommy tippee cup and this week have managed to get her to take 150mls but it takes 2 hours! So by the time we give up she's either tired because she's missed her nap or we've run into tea time! Our routine is:

7am bf
8.30am breakfast
11am bf
1pm lunch
3.30pm ff from cup
5.30pm tea
7pm bf
Then usually 1 bf during night

She doesn't nap very well so it makes fitting everything in without her being tired even harder!My plan was to get her established on the cup for her afternoon milk and then attenpt the same for mid morning. But then I was wondering if she could drop the midmorning milk altogether and bring lunch earlier? It's hard to know what to do - I'm worried about her not getting enough milk if I do that. What do other people do at this age? Thanks!

I'm back to work next month and here's what i do:

6am (ish) bf
7.30 breakfast
9 sleep for about 45 mins
10.30 snack _ it was 2oz of formula from doidy cup but he refuses it now he just has 2 rice cakes and some raisins
12 lunch
12.30 sleep for about 1.5 to 2 hours
2.30 small bf
5 tea
7 bf (he is currently refusing to bf in evening as he's too tired and it seems too much hard work for him to suck so he has ff then instead)
His afternoon bf will become a ff from cup soon as well.

She needs about 18oz of milk a day including what's in her food. If ds2 refuses bf/ff i add cheese sauce or extra milk to his meals or a yoghurt for afters to keep the milk intake up.

Hope that helps