My mum lost her dad last Saturday(April 30th) and since then, she hasn't been herself. Whenever she's alone, u can always see tears streaming down her face and a far away look in her eyes. Since that Saturday, she hasn't really eaten neither has she really been herself.
Tho, I think she was closest to him( they talk on d phone @ least once a day and share virtually everything), is this mourning Normal for a man who was in his late 70s or early 80s before his death?
Her disposition is having negative effects on us( as she really hasn't given us the same attention we used to get from her before the unfortunate event) and as d first child, I feel it most and I think it's my responsibility to help her out @ this trying time.
Problem is, I don't know how to go about helping her out of this before it turns into full blown depression.
P.S: I think this is the first time she's losing someone she's so close to

Y'all should spend more time with her, don't always leave her to be lonely... You can dedicate someone who will always keep her company all day long...

OP, give her time. Its not easy losing a loved one, no matter the age they get to. With time, the hurt will get dull and she will get back to her old self. You all should just show you are there for her right now.