She NEVER plays independently (other than to chase a cat once in a while)

I'm sorry, I know it's not funny, but that bit is!
Personally I think it's a lot to do with personality, and maybe also first children. Evie was (is!) exactly the same. She likes to be no more than 2" away from me at all times. Henry will play on his own a bit already - probably because he has to because he's never always had my full undivided attention.
It does get a bit better though. Evie's now old enough to understand that I'll play making things for a little while, then she can carry on while I make dinner etc etc.
She loves helping me with housework (Ok, so it's not helping as you or I know it, but at least she's not whinging while we do it!). So she'll do dusting or she'll pass me washing to hang up on the line, she likes to fill the washing machine etc etc. But everything takes a million times longer, and occasionally she'll only want to do the pink things (or whatever). Cooking - she adores cooking. Juliet's probably a bit young to really help, but she can have a bowl of dried beans or pasta and do stirring, and pour them into other bowls. Or sorting out tupperware. When Evie was younger I'd give her a pile of tupperware and get her to 'sort' it. She'd make piles with it, put little things into big things, and when she'd 'sorted' it, we'd put it back in the cupboard together, and she was really pleased that she'd done an important job.

If it's something that I HAVE to do, and I HAVE to do it now - like if I'm making a sauce that needs stirring and she's pulling me away, she'll get a firm 'No. Mummy needs to do this now, then we'll play'. Because I think she needs to learn that she can't always have everything she wants immediately.
Maybe generally just start her off playing, and then sit back a bit and try to get her to do it. Just really gradually remove yourself.
But I don't really know, I don't have any magic answers, which is why I have a clingy child and a messy house!