This is a case of someone's family member saying "Oh, you should stay in Ginza" in an off the cuff manner. I am not sure if this is the place to stay but there are many hotels close to Ginza. The person seems to be relatively "upmarket" and can afford a 2000 yen cab ride to Ginza central! I don't get the idea of staying at upmarket hotels and then people suggesting walking long distance with a baby.

Shiodome is another area close to Ginza with many hotels, as is the Tokyo Station/ Imperial Palace area with Peninsula, MO, Imperial, etc.

Also, there are comments about hotel rooms being small. Well, you get what you pay for. The Palace hotel (re-)opened a few days ago and their standard rooms are 46 SQM! That might be an interesting hotel, and it's not far from Ginza.

Whenever I have friends that wanna stay in Ginza or go to Tsukiji, I always recommend Hotel Gracery Ginza:

http://gracery.com/english/ginza/

And the google map:

https://maps.google.com/maps?q=hotel...20223&t=m&z=16