@toni123 You're not measuring so you don't actually know how many calories you're eating. Since you've gained weight and strength, and don't mention being hungry all the time, you're almost certainly eating enough.
@crijptex I agree re under eating. I am shorter than OP and weigh 46kg and my maintenance is about 1600 cals. I also rock climb 3x a week (although bouldering) and lift 3x a week. Make sure you're getting enough fuel OP!
@crijptex I've been doing top rope/bouldering for the past 4 months actually and my grade has gone from a 5b to 6c+ in USA grades (16 to 23 in SA grades). Apparently this is quite quick progress but I had a baseline level of strength in my upper body when I started, my fingers just kinda had to catch up.
Honestly, I've noticed zero changes in my body from climbing (if anything I look worse because my legs have shrunk from not training them as much), but it's more of a fun sport vs something that builds muscle anyway.