This answer serves to show you can provide no evidence whatsoever. You simply assume it is true by granting it the benefit of the doubt while affirming all other wondrous birth stories in antiquity are false or maybe demonic.
First, your benefit of the doubt argument does not work because we could apply it to every unfalsifiable and uncheckable divine birth story.
Imagine there are 100 newspapers in the world and you think without hesitation that 99 of them are filled with false information and made up claims. Why on earth would you look at the 100th and just grant it the benefit of the doubt?
Newspapers can also be fact checked. Do you believe everything you see on new stations like Fox/CNN? I don’t, especially when it’s political. Same with some newspapers. There are papers with a good reputation and high standards of research like the New York Times. We also generally know the purpose for which articles are written and they are intended to be factual. We don’t know this for the Birth stories. They may have been theological within ancient conventions and nothing more. There is no fact checking or external corroboration of the divine birth stories of Jesus. We have no idea where the information comes from. It’s just there at the end of the first century and missing from many other streams of thought. What we have is a very common convention in antiquity that spans the entire globe of ascribing a wondrous birth to your god/saviour. Even granting Biblical inspiration, which I do, I no more need to interpret the infancy narratives literally than I do the Garden story. So even granting the Bible the benefit of the doubt I still do not have to take this literally. Both stories fall well into the realm of conventional mythmaking. In other words, the genre of divine birth stories is not historical biography and they should not be interpreted as such. But maybe Jesus really was born of a virgin. I don’t deny the possibility. I am just asking for evidence these accounts are credible as history as was stated. I can be confident the Biblical infancy narratives use real people and places and nothing more. But that is explicable since we know Jesus was an actual person and the writers very much so wanted to show his actual lineage. Both of the authors, probably writing independently, had to jump through a hoop to get Jesus out of Nazareth and into Bethlehem. The infancy narratives actually provide confirmation Jesus was born in Nazareth in my eyes.