Isaiah 8:3 (King James Bible) and she conceived and bare a son
Here in 2 Nephi 18:3, the correct verb form is the past-tense bare (the King James reading). What is interesting about this particular example has been the difficulty in getting editors and typesetters to use the correct bare rather than its homophone, bear. The 1852 LDS edition, the 1858 Wright edition, and the 1920 LDS have each had to independently introduce the correct spelling. For additional discussion of the difficulty in spelling the past-tense bare, see bear in volume 3.
Summary: Maintain the correct past-tense verb form bare in 2 Nephi 18:3 (“and she conceived and bare a son”).