Need advice about how to handle my teenage daughter.

[mrskode]

Getting over a migraine from 2 days ago, due to a teenage daughter causing stress.
She turned 19 today and was very rude to her 8 year old sister because apparently she didn't want any birthday presents from her. She refused to open them and said that she didn't want them. My 8 year old was heartbroken. I kept one present and gave some of the presents to my 8 year old to keep. Whilst the 8 year old was at school, my 19 year old went through the 8 year olds room and retrieved the presents because she changed her mind. I retrieved one of them back. I am fuming because the oldest one went through her sisters stuff. I am left wondering how to handle the situation.
I am thinking about giving one present back if she apologizes and another back if she does something nice for her little sister.

[Dad4good]

Hey @mrskode ,

There was post about a week ago where another parent was having a similar issue (i.e., their eldest was ignoring their younger child). Might be good to have a look through the previous posts (sorry, I had a quick look but couldn't find it). Anyway, you may want to reach out to the author of that post . . . 

Are there any other parents/caregivers who have been through this issue?  

[TOM-RO]

Hey @mrskode 

Thanks for sharing with us here on ReachOut. It's great that you're reaching out during times of stress. It must be hard to watch your innocent 8 year old be treated negatively by her older sister. Can I ask - is this sort of behaviour typical of your 19 year old or is it uncharacteristic of her? If it is an ongoing issue it might be helpful to speak with a child/adolescent psychologist or counselor. Parentline can be a helpful starting point for such services. The number for Parentline may vary depending on what state you're in. This link provides the numbers per state if you are wanting to call. 

I like your thought of only returning her presents to her if she apologises to, and does something nice for, her younger sister. Did you end up doing this? If so, how did it go?