Besides the word Almah, never has nor does it mean Virgin, (As someone else has pointed out) It is even simpler to decide if this could in anyway be a prophecy about Jesus
Isaiah 7:14-16 – (14) Therefore the L-rd, of His own, shall give you a sign, “Behold the young woman is with child, and she will bear a son, and you [or, she] shall call his name Immanu’el. (15) Cream and honey he [Immanu'el] shall eat when he knows to reject bad and choose good; (16) for, when the lad [Immanu'el] does not yet know to reject bad and choose good, the land whose two kings you dread, shall be abandoned.”
Every bit must be looked at as well.
At what age did baby Jesus mature?
What are the implications that Jesus sinned up to this age?
Which two kingdoms were abandoned during the lifetime of Jesus?
How could the Kingdom of Israel be dreaded during the first century C.E( the time of the Jesus narative)., when there had not been a Kingdom of Israel in existence since the eighth century B.C.E.?
Where is the account of Jesus eating cream and honey recorded?
if you actually study the history of Ahaz (the King Isaiah made the prophecy FOR), you'll learn that the two kings were Rezin and Pekah.
Israel had been invaded by Assyria. Ahaz was king of Judah, at this crisis refused to co-operate with the kings of Israel and Syria in opposition to the Assyrians. He was attacked and defeated by Rezin of Damascus and Pekah of Samaria (2 Kings 16:5; 2 Chr. 28:5, 6).
THIS is what Ahaz was worried about and THIS is what Isaiah's prophecy was about -- the two kings -- Rezin and Pekah. Not virgin births.
Read of II Kings (16:9) and you'll see that Isaiah's prophecy in 7 is fulfilled:
“And seized it and exiled its inhabitants to Kir, and he slew Rezin,” and in that very year (ibid. 15: 30), “Hoshea the son of Elah revolted against Pekah the son of Remaliah, and he struck him and slew him… in the twentieth year of Jotham,”
Ahaz sided with Assyria, fighting with Tiglathpileser against Israel and Syria. Ahaz and the Assyrians won (as Isaiah 7 prophecied).
Rezin and Pekah were conquered and many of the people carried captive to Assyria (2 Kings 15:29; 16: 9; 1 Chr. 5:26). Soon after this Shalmaneser subdued the kingdom of Israel. Samaria was taken and destroyed (B.C. 722).
But, true to Isaiah's prophecy in chapter 7, throughout Ahaz reign, the kingdom of Judah was unmolested by the Assyrian power.
The prophecy had nothing to do with virgins having babies, and very little to do with the baby itself. We see that the prophesy is completely fulfilled in the text of the Hebrew Bible, not partialy in a work written hundreds of years after the close of the cannon of the Hebrew Bible.