Petra's social skills are developing apace. She's much more animated now, more responsive to me and my actions, and more aware of her effect on me.
For example, I put her on her mat to play the other day and sat beside her drinking a cup of tea. She played quietly while I wasn't looking, chatting to and hitting the dangling toys. After I finished my tea, I lay down beside her. She became very animated once she had my attention, rolling on her side to look at me then rolling onto her back and beating at the toys with both hands. I was of course most impressed and the more I told her how impressed I was, the harder she bashed and the louder she talked.
That same afternoon she made her first joke. She leaned against me and sucked my t-shirt, then pulled back to look at me and giggle. She kept on giggling while I got organised to feed her (I can take a hint!), only stopping when she latched on to my breast.