Hi there
Sorry you didn't get a reply sooner.
By the time you go back to work your Lo will be almost 12 months so milk will be considered a "drink" rather than a food, her main source of calories and nutrition then will be focused on solids so I wouldn't worry too much about dropping the top up BF or dropping to 2 BF per day, that's fine.
I would be offering 2 snacks per day every day now rather than sometimes, plus 3 main meals. How about moving breakfast earlier (say 8.30) and having a snack at 10.30am? then another snack around 3pm? There is no rule about what the snack needs to be but some LOs will drop milk feeds more easily if they get some dairy elsewhere so perhaps think about a natural unsweetened full fat yoghurt or a chunk of cheese?
For the after lunch top up how about offering expressed milk in a cup or with a straw? At 12 months you can offer cows milk as a drink. Or again end the meal with a chunk of cheese (and drink of water)?
Some times they are teething which causes a drop in appetite although possibly not enough pain to disturb sleep or alter mood too much. This could be why she seems to be off food some days and a bottomless pit on others, she'll make up for the low intake days on another day. You could also try starting the meal with a very small portion of something she really likes, fruit or dried fruit to get her appetite going and then move on to the other main foods. I found this helped my DS when he seemed totally uninterested it just took a few sultanas to get him going and then he'd eat a big portion of proper food.
Either now or at 12 months I would probably just offer comfort and water in the night. There is plenty of opportunity for her to eat during the day and you've already said she usually goes through the night without needing to feed. If you start feeding more at night there's less chance of her taking all her calories on board during the day.
hope this helps