Walks: How far?

I know its been brought up before..because ive read it. but just not sure where.
How long of walks should a 13 week old pup be going on? she has only just started to walk this last week after getting her second shots.
she isnt a huge fan of walking..dont blame her with the cold weather (well its average of 6-4* at night..she has a coat..but do you think her paws get cold on the pavement?)
Each night we go for a bit longer..the first few nights.it was only a couple blocks (2-3) then wed turn around.
tonight it was our longest walk, 3.5 km..45 minutes.
she was SUPER excited when we turned around because she knew we were going back home..lol
and shes all happy now that we're back.

Shes still not doing her buisness on the walks..but im not too worried about that

I think you are just going to have to play with it. If she did a 45 minute walk that to me is long for her age, but if she was fine and happy with it then..... I think a tired puppy is a happy puppy.

I have always gone with that idea, and have pretty much always walked Fletcher 3 time a day (a normal day) if we take him somewhere or I have to be out in the middle of the day we skip the mid-day walk. When he was young would walk in the morning, not sure on the distance but it was a quick 20 minute walk, the another on the leash in the middle of the day again about 20-30 minutes, then we would go on our long walk in the evenings about 45 mins-1 hour. Once I stopped working when Fletcher was 4 months old, I got to extend the mid-day walk just because I have time. Then once September came and Mr. Monster started preschool and we live exactly 1/2 mile from the school I started walking Fletcher and Mr. Monster to school this meant we walk 1 mile in the mornings, another mile to pick up Mr. Monster from preschool mid-day and we still go on our long walk in the evenings. For me this is my de-stress time since I walk him alone. NO kids just Fletcher and me no worries about time or which way we go. I live in a neighborhood with extensive walking paths so its very easy for us.

I'm not sure the cold really bothers dogs as much as it does us. However, someone posted on CT about their dog getting ice chunks in their paws, I'm sure that wold be a different story. A pup, kind of like how a child will play outside in the freezing cold even if they forget their mittens or my personal favorite leave their coats unbuttoned, they don't care it all about the play. Old dogs I could see how the cold might bother them more, and the heat can be dangerous for any dog.