Complex sentence: It took until 1907 before the first branch of the NUWSS was formed in Wales, when a meeting at the Llandudno Cocoa House saw Mrs. Walton-Evans become the president of the local cell.
Split into simpler sentences: It took until 1907 before the first branch of the NUWSS was formed in Wales. This occurred during a meeting at the Llandudno Cocoa House which saw Mrs. Walton-Evans become the president of the local cell.