wa alykum as-Salaam warahmatulahi wabarakatuh.
masha Allaah some good ideas.
I was thinking that you could start the presentation off by asking all the girls what they know about eid ul adha, ask them their opinions towards it too. this might take upto about 5mins, wa Allaahu a'lam. (and Allaah subhanahu wa ta'aala knows best.)
After this, explain the situation of why eid-ul-adha exists, and why it is such a special event for the muslims.
you can check this link out insha Allaah for abit of info:
we can try to look for more info. too insha Allaah if you need any.
try to make it as a powerpoint presentation to keep the sisters interested. we can help you with that if you want, insha Allaah. so please ask if you need any help.
throughout the presentation, its good to answer any questions the sisters have - regarding the area your discussing, this way its going to show interaction between you and the audience and its going to make it more fun, and lively instead of it just looking like a lecture.
like sister halima has said, its good to reward them with things throughout the presentation, but i think it should be something better off. eg. instead of giving sweets as a reward for a presentation - the sisters will probably want to enjoy it, but this differs to the way kids think. instead the sisters probably want a place where they can chill out and discuss things with you freely, therefore if you got abit of money, or if the people you working with have some money collected - just try spending some on sweets which can be left in the room so sisters can take them whenever they choose, or some crisps etc.
this way - the sisters will think that its a chillout place and that learning about islam is more fun, and you can enjoy it - instead of having to be forced to sit there with nothing to do and listen to a 'boring lecture.'
something as small as that can make a big difference, because most people want a place where they can relax, and because the majority of the muslim places dont have any place for the youth - the youth go to other places where it may be haraam, because they feel more freedom there - hence its really important that people start contributing to make the muslim places more lively and fun, but its important to keep it halaal insha Allaah.
after you've discussed the main topic, and what its purpose is - you can do a small quiz about it. thats just an option but you can ask the sisters whether they want to do it or not. this way, if they say no - just act casual and say its ok. but at the end of the presentation - ask them questions, and see if the sisters will respond with any answers.
they should if they relaxed and feel comfortable there insha Allaah, because remember - they want to be treated as mature adults, but they want the fun of being a teen there too; so treat them with respect and at the same time, joke about with them for a laugh so they feel comfortable insha Allaah.
after the quiz, the time may nearly be over - but start talking to them about what they going to do on eid, what they want to do on eid. sisters like talking about clothes - so ask them what they would wear on eid etc. raise their spirits and make them feel excited for it, and give them time to talk about eid with each other.. take the box of crisps, or chocalates at the end and tell them they can discuss what they want with each other, just so its like a small social gathering.. this may make them want to come together as a group of young muslimahs more often and they may feel that its fun, and most importantly - fun in a halaal way, which their parents will even approve of insha Allaah.
wa Allaahu a'lam.
(and Allaah subhanahu wa ta'aala knows best.)
if you need any help on anything, or in any of the tasks - then please do ask insha Allaah.
wa Salaam o 'alykum warahmatulahi wabarakatuh.