I can't find anything that say anything about Elijah birth or mentioning it, he is first introduced as a grown man in 1 Kings 17:1.
Neither does anything state that Samson had the Holy Spirit from birth but rather that he was dedicated with a Nazarite vow from the womb just like John the Baptist was.
4 Now therefore, be careful not to drink wine or strong drink, nor eat
any unclean thing. 5 For behold, you shall conceive and give birth to
a son, and no razor shall come upon his head, for the boy shall be
a Nazirite to God from the womb; and he shall begin to deliver
Israel from the hands of the Philistines.” (Judges 13:4-5)
7 But he said to me, ‘Behold, you shall conceive and give birth to a
son, and now you shall not drink wine or strong drink nor eat any
unclean thing, for the boy shall be a Nazirite to God from the womb
to the day of his death.’” (Judges 13:7)
15 For he will be great in the sight of the Lord; and he will drink no
wine or liquor, and he will be filled with the Holy Spirit while still
in his mother’s womb. (Luke 1:15)
A Nazarite vow from the womb = filled with the Holy Spirit it does not say but we know Samson had the Holy Spirit when he fought.
5 Then Samson went down to Timnah with his father and mother, and came as far as the vineyards of Timnah; and behold, a young lion came roaring toward him. 6 The Spirit of the Lord came upon him mightily, so that he tore him as one tears a young goat though he had nothing in his hand; but he did not tell his father or mother what he had done. (Judges 14:5-6)
19 Then the Spirit of the Lord came upon him mightily, and he went down to Ashkelon and killed thirty of them and took their spoil and gave the changes of clothes to those who told the riddle. And his anger burned, and he went up to his father’s house. (Judges 14:19)
BUT also the spirit cam upon Othniel, Gideon & Jepthat;
The Spirit of the Lord came upon him [Othniel the son of Kenaz], and he judged Israel Jdg 3:10. So the Spirit of the Lord came upon Gideon .. Jdg 6:34. Now the Spirit of the Lord came upon Jephthah ... Jdg 11:29