Hi,
Well...there are people here who know more than I do, but I think the first thing to do would be to break her of her 'mommy's girl' issue.
Yorkies by nature are very protective and loyal to their owners. If she sees you as her person, and only you, this could create issues.
I would try to get everyone in your family to spend as much time alone with her as you do, and if that means you spend less time with her, so be it.
Gradually she should come to the understanding that everyone in the home is her 'person' and love everyone equally (but perhaps different ways). This might cause her to be less aggressive and snappy with your kids and others in the home, because she'll know you're all her people, and not just you.
Another thing is emotional feeding that you may (or may not) be aware of. Pay special attention to what you are feeling when your kids come close to Sukie. I think you'll notice that you watch more pointedly at the interaction, and however slight it may be, your heartrate will increase as you wonder if she'll snap at them again. Or...waiting for her to snap, etc. Sukie will sense this and feel this increased heartrate from your norm. This is a red flag to her that something isn't right with you when the kids are near her. She then reacts instinctively to protect you because in her mind, you're fearful of your own kids. lol You clearly AREN'T.
But Sukie doesn't know that...she only knows that when the kids come to play, mom's heartrate increases and she acts differently...mom must need protecting.
Make sure you're calm, serene, and try your best to speak normally when the kids come around to play with Sukie when you're near to her. Any fluctuation of voice, or pitch (even the slightest little bit that isn't detectable to another human)....dogs can sense. If you keep your calm and don't react to whatever situation may...or may not arise, Sukie will be more likely to believe everything is okay, and not lurch to protective stance.
Without a doubt, someone(s) much more knowledgeable than I am will be here to add things too.
I hope Sukie soon learns that mommy doesn't need protecting!
Keep in mind that it is a Yorkie trait though, it's natural for them to want to protect their loved ones when their loved ones seem 'off'.