Show!Alicent and Show!Rhaenrya were never going to experience motherhood (or marriage for that matter) the same way, when you take into consideration that Alicent was forced to marry Viserys (Rhaneyra was technically forced to marry Laenor, but even then they had an arrangement and Rhaenyra still had power, whereas Alicent didn't have that power or that arrangment).
Alicent was forced to have her children (Rhaenyra willing had children with Harwin a man of her choosing and did not have to endure marital r@pe. Even though she and Laenor didn't want to have s!x they agreed they would until they had a child. Alicent on the otherhand is quite literally summoned by her husband for s!x. S!x that upon hearing she was being summoned for began crying and during said s!x mentally had to dissociate).
While of course people can still compare them it always annoys me when people specifically compare their relationships with their children because the context in how these children came to be is completely different (and the fact that this is only ever used to demean Alicent). Therefore how these mothers view their children is going to be completely different. This doesn’t mean that Alicent and Rhaenyra don’t love their respective children it just means that the dynamics they have with those children are going to be vastly different.
Not only that but the way Alicent and Rhaenyra themselves were raised and the relationships they have/had with their own mothers (and fathers) is also going to impact how they raise their children.
Nothing to add cause this is an excellent analysis. Wish more people would acknowledge their different positions(in life and situation) and keep that in mind when talking about their mothering, but this fandom is allergic to actual analysis🙃