Matthew 1:25 And knew [ginosko {ghin-oce'-ko} Jewish idiom for sexual intercourse between a man and a woman]
her not till [heos {heh'-oce}; Until]
she had brought forth her firstborn son: and he called his name JESUS.
UNTIL', prep. [un and till. See Till.]
1. To; used of time.
He and his sons were priests of the tribe of Dan, until the day of the captivity. Judges 18.
2. To; used of objects. Obs.
3. Preceding a sentence or clause, to; that is, to the event mentioned, or the time of it; as, until this hour; until this year.
The scepter shall not depart from Judah - until Shiloh come. Gen. 49.
4. To the point or place of.
In open prospect nothing bounds our eye,
Until the earth seems join'd unto the sky.
5. To the degree that.
Thou shalt push Syria, until they be consumed. 2Chron. 18.
[Note. Until is always the same part of speech in fact, and has the same signification. The only difference is, that it is followed sometimes by a single word denoting time, and in other cases by a verb denoting an event, or a word denoting place or degree. The sense is in all cases to; and till may be used as its substitute, and in modern usage it is most common.]
Godd thing you are trying. In 1633 I explain that "Until" is but one possible translation for "eos". Another translation we frequently see is "till" or even "even to the time that". See, for example, Matthew 27:8 "the field was called Haceldama, that is, The field of blood, even to this day". This is why there is nothing in Matthew 1:25 to indicate anything about Joseph and Mary after the birth of Christ.