Yes, Denny's mum is alive tammyy2j. (AUST PACE) The last time she was mentioned was when Leah asked Zac if he had spoken to Denny's mum & if so, did she know when the funeral was going to be. Zac said that he had spoken to her & she said the funeral would probably be delayed given Zac & Leah's impending wedding. Initially they wanted to postpone the wedding, but Evie convinces them that Denny would have wanted it to go ahead, so it was decided "the show must go on" - which it did!
As for the funeral, I know there is a spoiler/rumour around that there will be one, but I haven't seen any actual pictures/stories etc around of it (say, like there was before Casey's funeral). That doesn't mean there won't be one of course, but I am not sure whether we will actually get to see it. I would have thought that Denny's mum would want to have the funeral near where she lives, rather than have it in SB?? The rumour about there being a funeral could have come about due to that photo we saw some time ago of Ash in a black suit talking to Billie (this was the first time we knew for sure that Billie was returning). Whether he was wearing the suit because of the funeral remains to be seen. There was also a photo of Evie & Josh around recently, with them down at the beach both wearing black. Some have said it was for Denny's funeral, but to me that photo looks like it could have been taken previously at the wake after Casey's funeral (but I may well be wrong!!). Having said all that, I hope we do get to see Denny's funeral.