Ok, first I want to say that my DS is not your DD. They are all different so please don't think how it worked out for me is what will happen to you. But sometimes it's good to know that it's nothing your doing "wrong", they just can't connect sleep cycles no matter what you try. It's a skill they need to learn just like walking and talking.
My DS was exactly the same and we tried everything, osteopathie, we hired a sleep coach, all sorts of sleep training, strict routines. Nothing made a ounce of difference.
Although the sleep coach didn't help my DS sleep better she did save my sanity. We got her at the 12 months point when DS was waking roughly 10/12 times a night. What she helped with was focusing on trying one thing at the time. At that point I was so desperate and I got so overwhelmed with all the sleep advice out there that ever time I started trying something new I would read something else contradictory which would make me doubt what I was doing.
Things that helped a bit was safe co-sleeping. It reduced the amount of waking and helped getting him back to sleep faster.
DS stopped breastfeeding at 15 months and I think that helped a little bit with the amount of times he woke up but I still had to walk him back to sleep about 5 time a night. It started to get a lot better at 2 and a half. Now at almost four he wakes once at around 2 am and I go and sleep with him. If I don't go and sleep with him he will probably wake another 2 times.
On the flip side he has always been a very happy and healthy child, his moter skills have always been ahead of his peers (was able to keep his head up from the day he was born, sitting at 3 months, walking at 10 months). Not a lot of tantrums, never bit of hit other children. So the bad sleep never did him any harm.
My advice would be to try things, because it gets better much quicker for many. But at the same time try to find a way to have peace with what it is. Accept that it's a skill you're DD just hasn't developed yet. And know it's nothing your doing wrong. There is no trick other parents have figured out that you haven't.