Or is SIL?

[Mumof1plustwins]

Or is SIL?
I'm peeved off with her for her lack of involvement in my children's lives. She lives 10 minutes away but she may as well live on the other side of the world.
MIL lives abroad but phones 4/5 times a month, DH and I are lucky to hear from SIL twice a year! She never bothers to visit her only niece (5yo) and last year rang me in the evening to say happy birthday to DD and to say she would get her DH to drop of DDs birthday card the next day!
And it got worse when my twin boys were born, she never phoned to ask when they were due or if we were ok and when she was aware (MIL told her) she didn't even bother to call me until they were over a month old, she saw them once and hasn't seen them since, they'll be 1yrs old in a couple months!
And just before Xmas they were admitted to hospital with bronchilitus, MIL told her but she didn't even text to ask if her nephews were ok!?
She only texts at Xmas to ask if me and DH are coming over (not likely with 3 kids and their dog that they know is NOT child friendly!)
So basically is it 'normal' that she not bother with her brothers family or am I expecting too much from her? She isn't a very busy woman, she spends most her free time at friends houses visiting their babies etc or at home.
I just wanted to ask to see how other people are with their families- this can't be the norm surely? :(

My sister and I are very much in contact and involved in our respective nieces and nephews lives. We speak on the phone almost daily and see each other a few times a week.

My DH and his brothers (one lives locally, one lives the other side of the country) have contact maybe once or twice a year. Any news is passed via MIL and they generally don't contact each other except for sending birthday/ christmas cards and presents. I know that it is slightly different, that they are brothers and not brother and sister, but they are generally not very interested in each others lives or their nephews and nieces. I'm guessing though, that my DH would help in times of need or whatever and vice versa, but they all have thier own separate lives to lead.