New York Journal of Commerce (March 13, 1846):

"SHIP LAUNCH. - Messrs. Westervelt & Mackey will launch tomorrow (Saturday) morning at 10 o'clock, from their ship-yard at the foot of 7th street, near the dry dock, the ship Margaret Evans, to be commanded by Captain Edward G. Tinker, and to take the place of the ship Toronto, in John Griswold's line of London packets."

New York Evening Express (April 14, 1846) - most likely a "press release":

"ANOTHER NEW AND SPLENDID PACKET-SHIP. - We have just had an opportunity to examine the new London packet-ship Margaret Evans. She is truly an extraordinary ship. Her length is 166, breadth 35, depth 22 feet, and of about one thousand tons burthen. She is built by Westervelt & Mackay [sic] of this city, of live oak, cedar, and locust, and is to be commanded by Captain E. G. Tinker, long known as one of our most experienced shipmasters. She is of a beautiful model. Her accommodations are most conveniently arranged. Her cabin is light and airy, and every modern improvement has been introduced to make her passengers comfortable and happy. The ornaments, decorations and finish are also of the most tasteful description. Between decks she is lofty and spacious. Her decks, steward's departmentment [sic] and forecastle are most judiciously arranged. Her knees are put together with all the precision of the best cabinet work, and the whole ship, within and without, is a model of skill that every nautical man must admire, and be proud of. She is named after the Lady of Joseph R. Evans, of Philadelphia. She will sail on Monday next, and belongs to Mr. John Griswold's old and successful London line of packets."

The latest voyage of the Margaret Evans I find is N.Y. to Antwerp in 1876.

And here she is:
https://collections.mcny.org/asset-management/2F3XC582T9CD