I have a 7 week old little girl. My husband and I would love to go on longer walks together with her (it would be a great way for us to get some more gentle exercise in, and for her to get more fresh air!), but I'm not sure how long we can take her out for in her pram. We've only done 10 minute walks so far. Any rules on this? How did other people do it? Many thanks in advance :)