Why is my sister not replying to me?

Basically in October I met my big sister for the first time…unlike me she doesnt live in the UK anymore so I got a flight and found her…we bonded straight away and since then I’ve been back to see her twice and she came to see me in the UK at xmas…we get on great, were sooo close and considering the 10 year age gap were exactly the same…when I’ve stayed with her and her partner we had loads of fun and I even worked with her for a while and met loads of new friends…shes always said I can go back and visit her anytime and if I want a job there then I can live with them for a while…Well, over the last few months I’ve been having trouble at home and need to get away for a bit and my parents agree it would be a great idea if I stayed with my sister for a while…I’ve asked her about it a few times and emailed her but she keeps puttin off talking about it and wont reply to my emails. I dont understand why…is she fed up with me already? Im so fed up at home I just want my sisters support and she wont even reply…help me :(