I do not have children, but almost every time I stay there I have seen families.
We had our 11 year old and 16 year old with us, hotel staff were very welcoming our kids enjoyed the pool the use of sand chairs and towels for the beach and the location.
Did not og With kids and did not think about that issue.
We had brought kids with us and the hotel accommodated to our needs as a family.
I was not there with kids but I would say the answer is yes. Unless you prefer to spend a little (or a lot) more and stay at a hotel with a swimming pool and be on the beach. If that is the case the South Seas is a good option and very close (and rates usually include breakfast).
I did not see many kids there but I found the staff very friendly and helpful and I saw no reason that this hotel would not be kid friendly. There are a lot of things to see and do close to the hotel, that kids would be happy and entertained. I could not believe that I could walk to most things and just leave the car parked.
Get an answer from San Juan Hotel staff and past guests.