10 week old joeys don't eat a lot of fruit or veg, they sort of grow into them as they get older the most important thing is that they are eating the staple. Still keep putting them on the plate everyday though, they do eat some even if it doesn't look like they did.
keep in mind an adults stomach is about half the size of your thumb nail, a 10 week old joeys is smaller than that, so they eat small amounts at a time several times a night.
bml is a strict diet when it comes to fruit n veg you should only be feeding the following.
Corn
peas
carrots
green beans
( if you buy a bag of mixed veg and there are lima beans in it that is fine too but there aren't a lot of lima beans in the mix )
apples ( no seeds )
grapes
cherries ( pitted)
melons- honeydew watermellon cantelope
blueberries
corn is not baddddddddddd for them when it is part of a nutritionally balanced diet like bml. In fact corn and the other fruits and veg is calculated in to help make it balanced.