An excess contribution of $2,000 is a correct result if you each have separate self-only HDHP insurance since each of you would be subject to a separate $3,500 contribution limit. You only get to split the $7,000 family limit if both of you were HSA eligible individuals and at least one of you was covered by a family HDHP plan (in which case you must indicate that both of you are covered by a family HDHP plan).
