My DD was smiling around 6 weeks, I think. It varies tremendously.

She hated the playmat the first couple of weeks I put her on it. She'd last about 10 seconds and then get upset by it. I persisted because I knew she'd end up liking the dangly things, but she really didn't like those until she was 2 or 3 months old.

She didn't laugh until she was about 3.5 months old.

She could handle increasingly long sessions of tummy time, now up to a max of about 5 minutes at a time (at 5 months). A minute at a time is just fine at 6 weeks. Make sure you do lots of those (10 times a day is what my MCHN told us). Often and short is the key to tummy time.

At 6 weeks, you are your baby's best toy. She is playing with you, your face, etc because you are the most important thing in her life. That is totally, totally normal. So do lots of games with her that let her explore you and your face and the ways you interact:

- smile at her, make different funny faces, lots of eye contact. Talk to her about what you are doing as you move around the house or go for a walk or whatever. A running comentary is good!

- move her closer and further from your face, so she can see the change. She doesn't understand about distances yet, but this might be funny for her, or at least entertaining.

- when she starts to say things to you (little "words" like ahhh and ohhh, and mmm), practise conversations where she says something and then you say something back. You need to wait for her - babies are slower to respond than we are, so you need to give her plenty of time to think and reply. She will love it if you repeat back to her the thing she just said to you.

She will get more interested in toys as she works out that her hands are there and how to use them. It wasn't until she really got her hands working that my DD had any interest in toys at all.

I am sure you have nothing to worry about, but it is fine to go talk to your doctor or your MCHN if you are concerned or you want to be sure.