I don't think she's going.
The Sussexes step back from royal duties on 31 March
www.hellomagazine.com
I didn't see anything about Meghan asking to co-host but I've seen elsewhere that Anna asked Meghalomaniac what she planned to wear and vetoed it. Anna allegedly also said the invite was only extended if she arrived with Prince Harry, not Edward Ennifull or anyone else.
So much for Meghan striking it out on her own in an attempt to establish herself as 'Hollywood'! She's nothing without a raggedy Prince. It's going to burn even more when some Kartrashian turns up in ill-fitting garb!