1. This applies more to Marie Rose than Jacky, actually. Jacky has good range. Prime examples would be 6PK, 3K, 66K, 4H+K, 6H+K, 66H+K, 6P+K, 8PP, 1P+K string and 4P. There's probably a few more but all in all I would say Jacky has good range.
2. This is NOT a weakness of Jacky but a weakness...