Just updating for anyone searching in the future, we had plenty of time. We flew from gatwick to Dublin and had so much time before our dublin-Boston flight that we spent almost 3 hours sitting in the waiting room.

We couldn't do online check in for some reason for the bos-dub flight but I got to gatwick early enough that I had the counter agent check us in and issue boarding passes.

When we got to Dublin we already had boarding passes and were flying with carry on luggage only so we used the flight connections route with no problems at all.