If your relative immigrated, don’t assume they only crossed the border or ocean only one time. It was not unheard of for immigrants to make return trips to the old country. Sometimes this was done to bring other immigrants on the return trip. The immigrant might have thought they wanted to go back home to stay only to realize that they really did want to immigrate. Some returned for short visits to family members for one reason or another with no intention of remaining in the home country.
Never assume that relative only made one trip to immigrate. That first trip could have been one of a series of voyages.