Look, sorry if this sounds snooty-well, hell no, it's not snooty or snobby to say someone/something is being stupid - but your mil needs a (metaphorical) shaking.
Seriously, those dogs are dangerous, they needed training. It's a matter of time before they attack somebody OR somebody gets so freaked out by their boisterous behaviour that they get so wound up they are round the police station demanding they are put down.
Because I would. Alternatively they could be rehomed with somebody other than your mil who isn't such an irresponsible idiot
Why don't people like your mil who are fundamentally irresponsible because she doesn't care about those dogs; because- if she did, she'd have trained them to be subordinate to ALL humans, as one day the dogs' boisterous behaviour will get them put down- stick to Yorkshire terriers; worse thing a yorkshire terrier could do is nip somebody.
Do NOT NOT NOT take any children round there.
Your mil sounds like a moron, sorry.
To have a rottweiller, you have to be an extremely responsible person.