[DNK]

Sounds like it's a female and holding from the behaviour. It's not alway obvious from froma bulging throat at that size. Each female is different. If they're only holding a few eggs it's less obvious as well.
I've only kept Malawis for around 8 months but have had numerous Demasoni spawn in my Dem/Lab mix tank.

Just keep an eye on it. Soon enough you'll be inudated with fry and holding females!

 

[DNK]

The link below should help alot if you've not already see it.

http://www.cichlid-forum.com/articles/malawi_bloat.php