We went to France when Rufus was 5 months, it was for 2 weeks & we needed ALOT!
I think you are

if I remember rightly, so that reduces things somewhat! I had to take steriliser, bottles, extra bottles, and I took premix formula because I was worried about the difference in water (lucky we were driving with the weight of all this!
Just think through all the things you need in a day for feeding, changing, sleeping, eating etc
Eating (by 8 months I imagine she'll be eating some food) ... BLW makes things much easier, she can eat what you are eating, no worry about faffing with mushes etc. Highchair of somesort would be useful!
Where will she sleep?
Do you need a travel cot, blankets, sheets, sleeping bags, blackout sheet/blind, fav teddy/comforter, dummies, monitor etc.
How many nappies does she normally use in a day/night?
Nappies, wraps, Wipes, Wetbag, wipes solution, liners, nappy creams etc
Clothes - for all weathers, layers are good as you never know what the temp is like in other people's houses or if you'll go out etc ...
Muslins, calpol, thermometer, Red Book (just in case) teething gel ... any other medicines etc you might need.
Suncream! Hats, Shade for pushchair, or large light muslin type cloth to totally cover her if asleep in pushchair, depending on how warm/where you are going - mozzynet and insect replelant.
Will you be swimming with her? - Swim nappies, floatseat thing etc ...
Toys! For travelling & while you are there, don't assume you'll be able to buy there, depends where you are & costs can be higher.