It depends what you want to do and see while you are in Tokyo as to whether Sumida is a good choice. There are a number of tourist attractions within Sumida, such as Skytree, sumo wrestling and the Sumo Museum, the Hokusai Museum, aquarium etc. If you are interested in shopping or nightlife, it may be a less appealing choice.
There are a number of stations in Sumida. The hotel should tell you which one is closest, and how to access from Narita. The JR Sobu line rapid service goes from Narita to Kinshicho which is one station away from Ryogoku. Other parts of Sumida are better served by Keisei lines.
hey it is not so bad! Look at a google map for Sumida. You are right across the river from Taito ward. You are (without 6 yr old. ) a 15-20 min walk from Asakusa's temples. Great for the kids to get snacks and see all the Japanese kids on their school trips and such. maybe some kids will practice English on you guys. Happens a lot here with students. Also look west and you will see Ueno zoo/park and Ameyoko shopping street. All about a 20 min walk from Ryogoku. A taxi home from Ueno area will be 5-7 minutes, if the little one is tired. Lots of shopping in both areas and plenty of coffee places to keep you going!
There are many stations(areas) in Sumida Ward, such as Ryogoku, Kinshicho, Oshiage, Morishita, Kiyosumi-Shirakawa, etc. We should talk about each of these, and not the Sumida Ward. Are you considering to stay at Ryogoku Area? Then, you should ask about it. There is the Sumo Stadium "Kokugikan" and also is a nice, popular Edo-Tokyo Museum as follows in Ryogoku.
If you are at Ryogoku station to go to the airport it will involve transferring at the next station Kinshicho. Then going straight to the airport. Ryogoku is actually two separate stations. If you look on google maps and zoom in, I am talking about the one nearest the river. The Sobu Main line.
We just stayed in the area for 2 weeks near Skytree. Oshiage Station was our Metro and its not a bad area. Much much quieter than the main areas and does take a while to get to Shinjuku/Shibuya, around 50 mins with a number of changes on the Metro which can be confusing. With kids it may be more difficult considering the amount of people in stations is full on no matter what time of day it is.
Thanks. This helps