Congratulations, frufru! My advice would be to hold back on any big buys until you know just what DD and her OH want. It's easy to get carried away, rush out and buy something like...oh, let's say for instance a lovely gliding crib for £150 that only suits a baby up to 10 weeks old, takes up room you haven't got and is used once because they prefer the much more practical Moses basket (I can't imagine who would do that, btw
).
By all means enjoy buying some cute growbags and muslins, but do remember that the new mum and dad will be excitedly looking forward to choosing their own things. Ask them what they want from you much nearer the time.