I am feeling very upset with my younger sister. Maybe I am being unreasonable but I feel I have good reason to be upset. My niece will be ten in four days time and I have sent her a card and some presents. She is the daughter of my older sister not the sister I am upset with. My older sister and her family have just moved house and I do not have their new address yet as all my family live in another country (within the UK) and they are not good at keeping in touch. I am the one who makes the effort to do so as I am the one who moved away. My younger sister lives near to them and knows their address but will not tell me it as she says it is not her place to do so and my other sister will be sending out change of address cards soon - but not in time for me to get the birthday present to my niece. So I asked if I could send the present to my younger sister's house as she will be visiting my older sister on niece's birthday. She said yes that was fine so I wrapped everything up and sent it off. Today I phoned her to see if the parcel had arrived and she told me yes and the presents were gorgeous and niece would love them. I was a bit bewildered by this and asked her how she knew what the presents were and she admitted she had opened the parcel and unwrapped the presents. I asked her why she had done this and she said it was because she was not expecting a parcel so she looked to see what it was. This was a lie as she did know what the parcel was as I had phoned her to say it was on its way. I asked if the parcel had been damaged in any way thinking that might be why she had opened it but she said no it was fine. The parcel was very clearly marked to my niece, had my sister's address on it and she knew it was coming. She had just opened it because she wanted to look at the presents. I asked her to re-wrap the presents and put new gift labels on but she said she didn't think it was necessary and she would put the presents in a carrier bag and tell my niece who they are from. I am so annoyed with her and very upset. Maybe I am just being unreasonable and I will have to let it go anyway as I don't want to fall out with my family but I am really fed up with her.