How old is she?
I have one in Montessori and one starting next year.
We still do lots of work at home, and I probably will for many years.
For my oldest (4), I do
handwriting (he chooses usually, or I just lay something out...we have dot to dot and maze books, handwriting without tears kindergarten book and tools, tv teacher number beats and book, and kumon write and wipe letter and number cards)
Math (MathTacular DVD and associated games, home-made manipulative adding games, board games using two dice reinforce adding). I think an important thing to remember about math and montessori is that it's a constructivist philosophy. The child handles the material over and over and over and then it's in their head forever. And I do think it's etched a little differently in a child's mind than if they had only memorized facts after minimal manipulation of material. I've had a hard time finding the perfect supplement, so I mostly make my own. But, practical life math is good...cooking while talking about fractions, my kids always do math with their breakfast cereal (the oldest gets three bowls to manipulate his Kix in and a stack of addition flash cards to discover the answer...he made this up himself). We also have a large laminated 100 board on a wall ($2 at a teacher store) and he points while I count since he hasn't mastered this yet. But we can also use it to make skip counting patterns, etc.
Reading: he reads to me everyday and I read to him everyday. I monitor his progress carefully and make sure he's always stretching.
Spelling: we're using All About Spelling 1 and I LOVE it.
Latin: Song School Latin, occasionally
Spanish: Whistlefritz, and just us attempting conversation in Spanish (he also gets it at school, and I only had 2 years in high school..we're about the same level but his pronunciation is better).
Science: We're reading Usborne Chemistry book and doing the associated experiments. He also watches bill nye, they might be giants videos, beakman's world, and we go to a science museum weekly.
Geography: I show the kids a famous landmark every morning until they both know it, I also do this with other things (like Presidents and Animals, and our Van Gogh bits), we put a sticker on a state on our big map everyday and talk about that state.
Time/Date: we have a kids calendar and pocket chart to show analog and digital times and events of the day.
Vocabulary: we do a new word from Vocabulary Cartoons daily
History: we are listening to "Childrens History of the World" audiobook.
Critical Thinking: he's going through Critical Thinking Skills:Primary from Critical Thinking Co
Practical life: Regular house life provides plenty. I make sure he puts things away as he goes (I rarely remind him now), he is in charge of his own things-makes his own bed, brings his lunch box to the kitchen to clear out and put in the dishwasher, helps with other various chores--all stages of laundry, sweeping and mopping, washing dishes, getting mail, etc.
Music: we are doing a slow composers study. If he'd allow it, he'd be taking an instrument class as well, but it has not worked out so far.
Some days, he is tired and we just watch educational videos or I just read aloud to him. I try to do handwriting everyday right after school while I prepare a snack (if he finishes quickly, he'll help too), then we can sit at the table together and either do All About Spelling, Latin, or Chemistry. Some days I'll skip it because I know he just can't. Some days he begs for more. You'll know.
For us, the two most important things have been to maintain his "put things away as he goes" like he does at school. It's just (mostly) automatic now. My almost 2 year old is doing fairly well in this department too. And usually manipulatives in math (unless my child himself says the whole thing without..I am never the one to say let's try it without).
Good luck! There is still lots you can do, you may just need to be more flexible.