I understand your concern and frustration, mine was the same!
Honestly when you ave done everything you can do, including monitoring growth, seeing a paediatrician, cutting back on solids etc there isn't much else you can do but accept she's not a milk lover.
Whilst I'm not saying her milk intake is perfect or average, looking at the feeds, it may not be as bad as you might think. LOs this age can become extremely efficient feeders at the breast so whilst she might not be feeding for long she may well be taking what she needs. She probably is taking what she needs, babies generally do and her growth rate is showing this.
The 'norm' at this age would be 4 milk feeds, around now the 5th (dream feed) is dropped. You still have 4-5 milk feeds in her routine even if they are not all full milk feeds so again it would indicate to accept this is her way and she is ensuring she gets what she needs.
I would continue with the milk and solids feeds as you are. Make sure her solids are balanced (ie that she is not having too much preference for one food group such as fruit) and if she like dairy solids give her an extra portion of cheese, yoghurt, milk pudding, white sauce. Some cheeses are higher calcium than others, some are higher fat (ie full fat ricotta), tofu is also a high calcium food.
If she isn't keen on dairy solids you can add calcium to her diet by serving dark leafy vegetables such as spinach, broccoli and kale, almonds (not whole nuts at this age but ground almonds can be used easily in baking eg sugar free banana and almond mini muffins or pancakes made with egg, ground almonds, banana and milk). You can increase her fat intake by adding butter, oil or coconut oil to some foods, serving meat, oily fish, avocado, eggs, ground buts or nut butters (smooth not crunchy, ie smooth peanut butter, again this is something that can be added to baking).
Possibly more work for you but it is also possible to add some milk powder to certain foods which would increase the 'milk' (milk powder is usually fortified so there are added vits too), or you can try cooking with cream, evaporated milk (double calcium). Whilst alternative milks must not be given as a drink and must not replace either BM or FF at this age it is ok to use other milks/creams in cooking.
My approach to feeding was that every mouthful had to count, no 'empty calories'. I felt this was especially important as my DS took so little milk but like yours he grew well. Mine was on 3 solids meals almost right away when we started solids. If you keep an eye on what you are offering her there is really no reason not to offer 3 solid meals plus the milk feeds.
It might make you feel better to know that mine does still drink milk at almost 5yo. He takes 150-200ml in the morning, more in his cereal and once in a while asks for a cup of milk before BT (it's very small though). He loves all sorts of cheese and eats oily fish and fish bones (not suitable for babies but when she is old enough sardines or sprats are great source of calcium as the bones are eaten, mine like crunchy sprats and eat the head and tail too). He's never been a chubby baby or toddler but he has followed his growth line perfectly. Taking less than average milk doesn't always mean there is a big problem.
hope this helps some