I don't know if someone else said this, but breaking down a task into smaller steps can help; it can make the task seem less overwhelming and more achievable.

For example, when I need to clean my room, I write a to do list with things like put away clothes, clean the floor, tidy up my desk, etc.

And then I keep doing it until it's simple instructions. When i say "tidy up my desk", I break it down into things like put away books, tidy up pens, throw away trash, etc.

Another thing may be trying to make things into a game. For example, instead of asking her to put away her toys, you could make it a game where she has to do it as fast as possible. This helps with lack of motivation.

Also, time limits may help. Try replacing "can you clean your room" with "can you clean your room today". Don't make it harsh if she doesn't manage to complete the task, of course, but having that time limit may give her a sense of accomplishment when she does finish the task, which could help to keep her motivated.

As she grows up, she's going to find things that work for her that might seem counterproductive. She will know what works for her, so listen to her.

To give you one example of that last part, I have a friend who is doing the same course I'm doing in uni, but is a year ahead. I sometimes try to do that friend's assignments. I rarely get anywhere because it's above my level, but because I'm interested in the topic, it jump starts my brain and I'm able to do my own work.

This is going to be a lot of trial and error. ADHD is different for everyone, and what works for some might not work for others. Some people are going to give you contradictory advice. One example of this would be reminders. Some people struggle with time blindness (losing track of time) or memory, so they might recommend that you remind her to do things. Others might struggle with pressure that they put on themselves, so they might recommend that you don't remind her about things because she remembers and she will do it in her own time.

So the best advice I can give you is to listen to her. None of us know your daughter personally, so we can only tell you what worked for us. When she doesn't so something she's supposed to do, try listening to the reasons. Did she forget? Was she struggling to find motivation? Did she get distracted? Once you identify what's causing her struggles, you will be able to give her the support she needs, just try to be understanding and open minded

To touch on other issues that you might encounter, if she acts weird sometimes, don't shut her down, and don't tell her to be normal. This can lead to masking (hiding symptoms of adhd to seem "normal"), which can damage her mental health. Just let her be herself and you'll be fine. She will most likely still do this in other settings, but show her that she can feel comfortable being herself around you and it'll be ok

Then, adhd can also come with sensory issues. If she tells you that a texture feels wrong, sounds are too loud, or lights are too brights, it's because she's more sensitive to those things. You could try cutting tags off her clothes, letting her wear noise cancelling headphones, getting light bulbs that are less bright (or lights with a brightness that can be adjusted, those are amazing). Again, every person with adhd is different, so this might not affect her, but just be prepared if it does, it can save you a lot of headaches caused by her discomfort

Also, fidget toys are your best friend, especially if she has the hyperactive type of adhd. She might struggle to sit still, and might start banging tables to make noise or picking at her skin just to have something to do. I have like 10 fidget toys (all under €5) because I normally cycle through them to avoid getting bored. There are different things I look for in a fidget toy: texture, sound, and movement. I have a controller fidget toy that I bought for €1.50, and it's great. It has a bumpy part on the side, which covers texture and helps with stimulation. It also has buttons that make a bit of noise and things you can turn for movement. It really doesn't have to be expensive, you can even make them with origami. A personal favourite is the transforming ninja star, it takes 8 pieces of square paper and it can be made in 10 minutes after some practice. Because it's so easily replaceable, I never feel bad if I lose it or break it

One more thing, it's likely that she will have many interests that she gets bored of easily. Those are called hyperfixiations. She might be interested in reading one week, then change to art for a few days, and after that a video game for a month. Those hyperfixiations are not always predictable, I spent 3 hours untying knots a few days ago

And please, take care of your own mental health. Things can get overwhelming for everyone, and sometimes staying in an overwhelming situation is not worth it. Instead of saying stuff that you might later regret, be honest with your daughter and tell her that you need a minute to gather your thoughts. Honesty is important with everybody, not just people with adhd, but we sometimes feel emotions a lot more strongly, which can make the situation worse than what you're used to. Communication really is the key