How can I apply the same stroke to multiple textLabels

I wouldn’t recommend having them share the same parent. Instead, I think it might work better to stack one text label directly under the other and set the size of the second text label to {1, 0, 1, 0}.

If you’re looking to show both at the same time without using two text labels, you might need to use some external software like Photopea or Photoshop. Although I’m not 100% sure.