When I've read about the scope of the job that Rebecca holds, it reminds of the jobs found in a startup company. Each person has a strength and is just adequate in other areas. But it's enough to get by and make money until the company develops base customers with consistent sales numbers. Then it's time to hire employees specific to the tasks so the base group of start-up employees are freed to do what they know best to foster growth.
Now, it seems that many of her office staff have reached a level where they no longer can smoothly coordinate all of the duties that are required. Sometimes it appears that no one has reached out to SJP or BP for advice with the fine details trip and engagement planning such as appropriate symbolic use of colors, clothing and activities. Sometimes, there shouldn't be a walk-about; just a procession to the engagement destination with foto ops. The host should arrange for a receiving line where the guests move and the duke/duchess stay in place. It's possible to do outdoors as well as indoors.
The role of private secretary shouldn't be combined with personal assistant. The scope of each job is too much for one person to handle adequately at this point in time and going forward. Private secretary and personal assistant are two different sets of responsibility and though they need to liaise they don't handle the same tasks.
She needs a permanent stylist who has knowledge of dressing expectations for destinations outside the UK. That person has to have a sense of decorum for the position -- and the ability to insist that the duchess dress for the function despite her desperate need to show off her figure at any mention of casual wear at an engagement. The current employee doesn't have that. The hairdresser that travels with her has moments of good style and the rest are meh.
Her staff needs an overhaul.
Will no one at SJP or BP step in and show how it's done properly? If her mum has been advising her, then mum has reached the limit of her knowledge and experience for this stage of her daughter's obligations and expected progress in the RF. The duchess should have been further along in adapting to her position by now. Either she's been given bad information so far or no one has insisted that she perform publicly as the RF duchess that she is. It's time to step up and draw the line between public appearance standards and private life.
Further to your comment vis a vis Mum as advisor, we know that at every moment of crisis in Kate's life she has turned to Mum to advise and overhaul. The solution appears to have been a self presentation overhaul rather than an intellectual one. Good for making teen boys like you, not so good for winning over the public.
We shall not see any growth with Kate until Carole is removed from her. I don't mean that in a horrible way. Kate will not seek any other advise nor will she follow through on anybody else's adgice therefore what we see is the result of Carole's advice. Since Kate is not a curious person, and Carole seeks only the Sloane Handbook, this is the limit of possibilities for Kate.
Further, PP was only a mom and pop shop, so no chance for Carole (and Mike) to evolve into the type of business that requires boardroom activities and directors and intersection with other businesses which means she's never evolved into the type of business person with a skillset that can be transferred to royal life via imprinting on daughters. Like Sophie.
Throw into the mix someone with no appropriate work experience like Rebecca, who apparently didn't learn a thing when JLP was in charge, and it's a disaster.
Pippa is more likely to evolve because she shows some curiosity outside of Carole. It's not much, but it is there.