Is this destructive or normal behaviour?

Is she bored. Perhaps give her more ideas for play. Not all kids have lots of imagination to think of things to do. X

Cupboard door locks? If she wants to behave like a toddler treat her like one.

She seems to be targeting things that she sees as your area, cooking and cleaning. Perhaps she wants your attention, some jealousy about younger siblings. There needs to be consequences for her behaviour but, most of all, you need to talk it through with her, without anger, and listen to what she says. Give her a chance to explain her behaviour, and keep on listening. You can also talk through the consequence. You had to spend time clearing up, so she should spend time helping you with the cleaning this week. Taking away her iPad is not relevant to her misdeeds, and will make her angry and resentful. Cleaning up is relevant, and may help you renew your relationship.

Sounds like she is trying to seek attention

She thinks you care more about cleaning then about her and she's testing that theory (subconsciously). I've noticed this behavior in homes where the parent prioritizes cleanliness over spending quality time with the child. Punishment in this case will reinforce the belief and ultimately worsen the behavior. My education is in child development and work in child care.

If you do spend quality time doing things she's enjoys often, then this much impulsivity at this age could point to a different underlying problem. (For example ADHD).

Could she or another child be just grabbing handfuls of sugar to eat and spilling some in the process?

Maybe it's a sensory thing? Try and find something she can do to appropriately satisfy her sensory curiosities. But all you can do really is to explain to her about damage, hygiene, and monetary issues and maybe tell her that next time you will have to insert appropriate punishment if she continues to not listen to you about these things (And also the problem of lying).

9 isn't a toddler but my daughter is 10 and I sometimes forget she's still a kid and she has blips where she blows my mind completely, they are still quite immature in ways at this ages regarding consequences.

It doesn't sound destructive to me. It sounds impulsive and experimental, without an understanding of consequences.

Cleaning sprays shouldn't really be accessible to a child, so you could easily get a lock on the cupboard it's in. I use a BeeGo lock for our knife drawer because DD1, who has LDs, is impulsive.

The real test, I think, is to explain that taking sugar without asking isn't ok, then leave the sugar in its normal place and see what happens.

Maybe it’s attention-seeking, or jealousy of her sibling? Could you find some collaborative tasks/crafts you could do together, maybe? Why not buy some cornstarch and get her to help you try and get the baby oil off the wall? It could put a constructive spin on what was a destructive act.

Punctuation edit!

My niece is 9 and she has me on edge. I am very wary of her as she has hurt my nephew several times.

She has stamped on his leg causing a hospital stay (other hospital stays for different things) she has stolen things out of our handbags, won't speak unless she wishes to even in school, she's had every assessment and nothing.

I'm no expert but it sounds to me like very low impulse control for a 9 year old. If you haven't read it, How to Talk so kids will listen... is a book I found interesting, digestible and helpful. I think it's more aimed at parents of a slightly younger age group but it's maybe no bad thing when she is doing things that are maybe more common in a younger child.

At school they'd maybe do ABC charts. The A bit is antecedents - was happening with the child just before the incident. It might be worth jotting down some notes and seeing if you can spot a pattern - kids might not know themselves that they do these things when hungry or angry or bored.

Talk to her teacher too, see if they see anything similar. If the answer is "no" is she masking at school, or is there a trigger at home that isn't there at school or is managed somehow by the structure there? I'm not saying she has no responsibility here but the more you can understand where she's coming from, the better you can fix it.

I’m struggling to understand the focus on cleaning, and why your DD ‘creates mess’. It sounds like you spend a lot of your time doing housework. I don’t know anyone who owns starch spray, for example (perhaps you run an ironing business?). Maybe she’s trying to understand what all the potions are for (I certainly am!!).

I think a weekend of no iPad for what might have been an accidental spillage is overly punitive. A chat about why she feels the need to spill/empty things might help you understand things from her perspective.

I’d maybe say to her you’re not angry but wondered if she knows and suggest reasons like “I quite like the noise/smell/etc, I wonder if that’s why someone was spraying it even though they weren’t doing ironing” to see if she opens up a little.

I did all sorts of idiotic stuff as a kid and my mum used to lose her rag a lot about it (understandably at times). I couldn’t always explain why because I didn’t have the words or understanding to say I had poor impulse control. Now I’m an adult, with a diagnosis of ADHD, I can recognise why I touched things that were hot just to see or ate a whole bag of marshmallows and was nearly sick! I’m not saying she has ADHD at all, more that kids sometimes need us to help them find the words to explain and communicate.

I’d definitely still try the cornstarch - I did it a few weeks later and you couldn’t tell looking at the wall now!

Mine are late teens now, but I'm not an expert on consequences as I just used to tell mine off. I hope someone can advise.

That isn't normal behaviour at all, not for a child of 9 anyway.

What I liked about the books was the discipline was done in quite a positive way. Charlie Taylor who wrote Divas and Dictators has run schools for kids excluded from other schools and his positive methods work on those children so he knows what he's doing. (I'm not saying your dc is that bad, just that he is experienced

The first two sound fairly normal. The last two you mentioned do sound quite naughty. Did you tell her off? I'm guessing you did. Maybe you could issue some sort of consequence?
I found the book Divas and Dictators quite helpful. Also Little Angels by Dr Tanya Byron. Although that might have been aimed at younger children, I can't remember. 💐

When you ask her if it in an accusatory way or a curious way? Spraying a whole bottle of starch is quite odd and the sugar could have a range of explanations so I’d want to know more about why. If she’s doing it to watch the world burn its destructive but if she’s getting mad impulsive thoughts she can’t resist it’s maybe indicative of more going on.

Also have you tried putting on a thick layer of cornstarch on the baby oil, leaving it in for a few days then gently dusting it off? My partner got oil on our freshly plastered and painted wall and the only reason he’s lived to tell the tale is cornstarch 😂