Holidays

Should I still buy Christmas presents for my nieces? What age do you stop buying them gifts?

I have an 8 year old daughter and a 10 year old daughter to buy presents for. I also have an 18 year old niece from my sister who I see a couple times a year (they live in a different state) and my husbands sisters kids are (16, 13 and 11) who I see a lot (they live in the same town, right down the road from us). My sister hasn't bought my daughters anything for their birthdays this year, or Christmas last year, or their birthdays last year, or Christmas the year before that. But she did get them something for their birthdays in 2014. I haven't got my niece a Christmas or birthday present since she was a freshmen in 2013 she's now a senior. I have gotten my husbands sisters kids gifts each year for birthdays/ but I see them often and their mother gives my kids gifts. My sister was planning on coming down to visit December 23-24th and bringing my niece. My sister was planning on getting my daughters gifts for this Christmas and past Christmases and Birthdays. She is getting them expensive clothing and electronics too. She bought concert tickets for my one daughter for next year. I think she is spending close to $800 on my 10 year old and $600 on my 8 year old. I feel like I have to now buy presents to make up for the 18 year old. Her mother said to buy her Amazon gift cards and bath and body works gift cards. How much should I spend not he 18 year old, or should I just not get her anything?
Updates
+1 y
I still have to buy Christmas gifts for my own kids and my other nieces which are pretty expensive. My sister is pretty rich and that 18 year old has been spoiled rotten her whole life. We don't have that big of an income at my house.
Updates
+1 y
I mean I feel like I should get my niece something close to what she's spending on my kids because if I don't my sister will cuss me out and go apeshit.
Should I still buy Christmas presents for my nieces? What age do you stop buying them gifts?
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