The Divine love had favoured the young Suhni from the infinity. (In addition) she discovered the worthy personality (i.e. the Prophet) who was symbollically the Divine, (or her) necklace. Coincidentally her discovery has proved to be a very safe ford, because the hopes of the mankind are pivoted on it (i.e. it has usefully served and shall continue to serve the whole humanity.) (The Prophet is the mainstay for the entire mankind).
Note: There is yet another interpretation of this verse. If we identify Suhni with the Prophet of Islam, then the verse may be translated as under:
From infinity the Prophet was favoured by Allah. (There is a tradition that the Prophet was appointed as the apostle even when the clay mould or skeleton of Hazrat Adam was not clothed with flesh.) The Prophet was solely considered quite eligible for the unique honour. He was worthly to wear the Divine necklace.
باز گشت ازدم او ہر دو باب
در دو عالم دعوتِ او مستجاب
(Roomi)
The prophet's mere breath opens both the doors (of the two worlds). His blessing is acceptable in both the worlds.

Suhni from eternity was one by love selected,
With Lord's union's garland she was graced,
That bank she reached, where world's hope resides.

From the very beginning love had favored Sohni,
She had the garland of beloved's love round her neck,
She found the ferry upon which all mankind depends.