I was initially going to leave this as a comment, but the question got longer, so I'm writing a new post.
The presence of the fetus is a bit saddening.
I feel sorrow about the death of a pregnant being, but is it merely the death of a vessel?
What is the typical parent-child relationship among extraterrestrials?
How do they become independent from their parents?
How should we come to terms with the idea that the child born is actually an entity that has existed for thousands of years?
Or is it possible that most of them are not born through pregnancy and childbirth, but rather their bodies are created in a biological factory?
This would vary by entities, but you can explain it using a specific entities as an example (e.g., Grey, Ashtar) or summarize common aspects.
I sincerely thank you in advance for the effort you put into writing your response 💛
Q: What is the typical parent-child relationship among extraterrestrials?
A: It depends on the group and their evolutionary level. For example, greys, a very diverse group can either see child avatars as vessels for soul transfers – or in some cases with hybridization with other species such as homo sapiens – may help raise the child, sometimes with the assistance of mantid beings, other humans/Ashtar, hybrids, or other races altogether. It greatly depends. It may seem horrifying for some grey groups to regard the little avatars like “drones” yet they don't see it that way. For them, their realme/spirit-soul is the true them. They are able to transfer their realmes at will and upload their consciousness to various avatars. When you reach this level of advancement, it changes your culture. While for many humans on earth, it may seem horrifying, consider these beings have the power over life and death in ways beyond imagination.
Q: How do they become independent from their parents?
A: Again, it depends on the group. Although technically speaking all species we know from the UFO lore are more or less hybrids or descendants from each other in some way or another, the reality is they are interconnected but have subcultures. In the case with greys, depending on the group – let's say Damien's group, they mostly operate as a (collective soul in multiple bodies). This may come across as hive-minded, but it's not so much that as it is that they are aware they're connected to a greater whole. They still maintain individuality because individuality does help as long as it isn't out of control in hyper-independence, which is both inefficient and unreal. In the case with these sorts of greys, they become “independent” in the sense when they are educated and developed enough – but unlike humans on earth who reincarnate and wipe their memories, these greys, do not. They maintain them, meaning even if they lose one vessel/container, they can soul transfer to another and re-upload their consciousness, allowing them to bypass the constant needs to grow up all over again – save for some biological natural aspects. As for the case with hybrids, such as Ashtarians and other human-like ETs like Elena at work with the federation above, they tend to raise their children similar to us down here on earth. The exception is that they do not pollute them with religious or political dogma, nor scientism, occultism, mysticism, and the like. Elena is practically a kindergarten teacher, for example. She (and others like her) teach schools above for growing hybrid children/human-like ETs. They learn practically every major topic in science to mathematics, art, culture, psionic abilities, how the spirit/soul works (no ideology, no mysticism, no teachings) in a practical, grounded and even scientific way.
Q: How should we come to terms with the idea that the child born is actually an entity that has existed for thousands of years?
A: By accepting the physical reality is not everything and is, in fact, subordinate just like how a car (vessel/container/physical being) needs a driver (spirit/soul). It just isn't, no matter how much we'd try to rationalize even in a pure (3D)-perspective.
Q: Or is it possible that most of them are not born through pregnancy and childbirth, but rather their bodies are created in a biological factory? This would vary by entities, but you can explain it using a specific entities as an example (e.g., Grey, Ashtar) or summarize common aspects.
A: Exactly. Not to mention, there are so many specifics that it's difficult to list them all. Some aren't born through regular pregnancy as we perceive it on earth. Others are born through (what we'd consider) artificial means, while some, a mixture between both – and more. It's so multilayered, diverse, and colorful that an absolute answer for all cultures and beings simply does not exist.