Baby will be becoming more aware of her surroundings now, and will love being introduced to new objects - especially those which feel different, look different, or make noises. This also means that she'll be much more easily distracted, and so feeding will be a little harder now. The other side of this is that her tummy is bigger, which means she can take more milk during each feed and may go down to between four and six feeds a day and still gain weight.
She can now also distinguish between familiar and unfamiliar faces, and knows the face of mom and dad. She will become attached to particular toys now, and may cry if they are taken away from her. Baby exercisers are perfect at this age - they will help her physical and mental development, and will be great fun for her, but don't use baby-walkers.