Maybe they don't allow her near the lake where they practice it,
Wasn't that lake some combination of 'clan heir training place' and 'obviously you'd practice over SOME water, you are literally playing with fire'?
I was under the impression that the Uchiha clan compound had more than one pond-type place, given how many Uchiha there are - elsewise, they'd either need to queu up for their turn, or practice outside the clan's grounds. Given the tetchy nature of Uchiha/rest-of-village relations right now, I'm disinclined to believe the latter.
or practice it in private rock gardens,
Generally rock gardens don't have rocks so large you can wholly and easily hide people behind them, and I don't recall seeing the Uchiha compound portrayed as an exception to that paradime.
So that leaves two sorts of wide, open, easily-viewed-from-a-distance sorts of places for training... which are the hardest of places to prevent someone from seeing.
or keep an active MIO watch while practicing.
Certainly possible, but I'd like to think that if something like this was happening, we'd have already seen reference to it in some of the updates where MIO visited the clan.
Given how many Uchiha there are, they'd kind of have to do it all the time, as there'd presumably be
some Uchiha practicing stealable techs at any given time.
That seems an unusually large investment of manpower, and I don't really see a benefit to them.
It'd pretty much have to be to stop MIO from picking some stuff up - and again, I'd ask why they'd bother.
It can be hard to remember it, but the pre-massacre Uchiha aren't
stupid. Unacceptably prideful, delusional over their family's secret history, drunk on their power - all of those things are true, but none of those things are outright
dumbness.
Which leads to the question; what do the Uchiha
get as a benefit, out of willfully restricting how much training an Uchiha-genius-kid can do, when they've already established a precedent of wanting that kid to be as impressive as possible?
It's less she's not allowed and more Mio doesn't care, mostly.
The Uchiha aren't practicing their fire techniques in the roads and eateries because if you fuck up then shit burns down, and Mio typically gives dedicated training areas a wide berth.
Sometimes someone as an individual will drag her screaming to a training ground, but typically Mio is decent at dodging them, they typically want to focus on clan taijutsu even when they do nab her, and the Uchiha clan as a whole tends to be happier not thinking about that kid who was born with the sharingan on right out of the womb and against every expectation of clan pride tends to wallow in smug mediocrity instead of applying herself.
They're also a touch to proud to go around flashing powerful jutsu in front of that one kid just in case she happens to start picking them up and actually living up to the sharingan hype for fucks sake how can you be such a disgrace.
Also, while Ma was alive she would straight up stab dudes who tried to make you live up to that clan hype, because she was watching you nearly die of exhaustion every day even without that extra pressure, and though that's settled down enough that doing things other than walking from your bed to food isn't a risky proposition any more, it sort of resulted in a combination of people being slow to forget that and Mio's habit of training negligence settling in.
I get all of what you're saying here, but I'm still having a hard time due to the specifics.
That is:
- If they were a smaller, less populous clan, it'd be far easier to believe that there weren't coincidental moments where Mio was looking in a direction while walking in the compound, and an Uchiha did a technique while in her field of view. But they have scores and scores of members, enough to field regular ninja and populate a village-scale policing force - that's a lot of bodies to clog up the compound/get in Mio's line of sight while they're doing shit.
- If they weren't so obsessed with making themselves look awesome/hadn't in-story mildly tortured Mio for failing to be maximally cool-looking in spars, I could buy them 'respecting' the precedent Mio's mom established. But Elders were willing to grab helpers to 'teach her a lesson' over something as minor as that - and here we are talking about a Sharingan'd Uchiha who cannot use fire techniques. Clan Head Fugaku had interesting things to say about fire-less Uchiha in general to his younger son, let alone to those that have them special eyes.
- If Mio's ma was still alive, I could see her continuing to nosell things despite the above two points.
But Mio's ma isn't alive, the clan isn't sparse and it
is stupendously invested in making its every member as cool as possible.
I mean heck, all it'd take is one Uchiha who's been tapped to ensure she's trained post-mom-death physically holding her eyes open and making her look at someone, and boom, she's at
least able to say 'yes, I
can use fire techs'.
Such an effort from pissed off clan members would take a minute, if that - given the ease of achieving that and the established precedent of them not giving a fuck about what she actually wants, it's odd that such a moment hasn't happened in all this time.
I'm just having a really hard time gelling this with what resulted from that one bout of lackluster spars, where her clanmates proved
exceedingly willing and able to ignore her wants and impose their own on her, and to do so
promptly to address a percieved issue.