Which hotel would you chose in San Francisco in April for myself, husband and 12 & 15 year old daughters: Stanford Court, Wyndham Caterbury or Marriott Union Square? Thank you!

I've also stayed at Marriott Union Square and really liked it. I don't know the other two at all

The location of the Wyndham appears better than Stanford Court.

Probably the Marriott Union Square. It's your typical Marriott hotel, so nothing really special.

It's walking distance to the shops, which maybe your daughters will like, if you feel they are street-smart to be walking around there. Because there is a homeless situation at Union Square, and you can get harassed by them. Just keep walking. Sad to say.

Canterbury would mean that 2 of you would have to share the living room sofabed, I think.

Marriott has rooms with 2 doubles and also rooms with 2 queens so you may wish to specify two queens

I don't know those particular hotels, but I've always stayed near Union Square. I think it's an excellent location for what most people want to see and do.