Yes, what lovely letters — although I should think posting pondweed would be a bit messy!
I enjoyed hearing about the frogs of all kinds, including the two Enid rescued (and the surprise they gave her husband!). Glad she was considerate enough not only to release them in the pond, but to wait for a warm day to do it so they wouldn't be harmed by a sudden change in temperature. It's nice how she always teaches her young audience to be caring and respectful towards the natural world — including toads!
I'm remembering now how one spring when I was about 6 or 7, my mum and my sister and I went tadpoling in the boggy fields over the road from our house. We caught a whole bucket of tadpoles and kept them for weeks, feeding them on boiled lettuce as a substitute for pondweed. It was so fascinating to watch them each grow first one leg, then two legs, then three, then four... When they were close to fully becoming little frogs, we put a piece of wood in the bucket so they could climb out of the water, and sure enough, they all made their escape over a few days. I would think of them whenever I heard frogs chirping outside in the summer. Those fields where we found them are all built over now, but there's a wetlands reserve very close by, so there's still a place for frogs and other creatures to live near us.
I haven't seen any celandines yet this year, but there are snowdrops and crocuses in abundance where I live now and the daffodils are starting to flower!