Sounds like to me it's a no win situation. If HMQ and Prince Phillip do gift her a new tiara, it'd be criticized they spent lavishly while people are suffering. If they don't and Harry does it, there will be chatter about how HMQ didn't approve of the union even though she had to formally give consent. They might as well just do whatever they want if that's the case.
And speaking of tiaras, if she were to get a new one, I think I finally realized something that would be perfect fit for Meghan. Something like the Modern Fringe the Swedish royal family has would look great on her. It has an element of classic fringe, but modern twist. It's formal enough, yet softer than the traditional fringe. I think that just sums up Meghan.