Answer:
Dear Lorraine,
How are you? I'm super excited about my plans for next Saturday and I'd like to tell you everything about it.
My cousins and I are going on an excursion to the Lake District in Cumbria. Actually, we're going to stay in tents at the banks of Lake Derwent Water in Keswick. We're going to go hiking in the mountains and sailing in the lake, which is amazingly beautiful.
The weather will be really hot and sunny. I hope you can join me! Let me know if you would like to have a fun time with me by the lake.
Love,
Maggie