I believe you are correct with brother-in-law (even though the "b" in brother is written entirely differently. The "B" in her first name, which Ancestry has transcribed as Beile, is written the same as the B in Bril. I believe I have seen other lists where it says br-i-l. On this list, it looks to me like "A. Kutner."
According to Ancestry's city directories for Lynn, Mass. in 1912, "Abram" Kutner lived at 180 Summer St. ("180 Summers St." on the passenger list)and he was a shoeworker.
According to the 1910 Census, Abraham's wife was Rachel. If Rachel is a sister to the person you're looking for, then A. Kutner would indeed be her brother-in-law.