It will take time for them to get used to one another.
Its normal.
Just be a little bit more patient and give them time to get to know each other.
Try to get a clean towel rub on your existing house cat and then take the same towel and rub on the new kitties.
This way you will be transfering your existing cat's smell to the new kitties and hopefully your existing cat will smell her smell on the new kitties and accept them.
Good Luck!

I feed blackwood it's not a top food but i think it's better than smart heart....? thats just my opinion.

i heard that dry food will help to keep their teeth clean. normal wet food if fed everyday might cause decay wor...... (i heard)

anyway once awhile I'll give my cat some meat to eat... but everyday I just feed her blackwood

ehh they change packaging already :0 my place always have blackwood, just that few months ago i went and buy the person told me the packaging is diff. Looks more classy xD

where do you stay wor? u can't be travelling all the way to somewhere far just to get it right >< there's this group of people that buy whoelsale and sell it somewhere near cheras. thats much much much cheaper. i bought the retail one @ danau kota

Ohh, I think sri petaling has a few petshop that you can check on. the packaging now is blue-ish if you wanna know Damansara area got a shop that I used to buy blackwood from also and it's really cheap! I stop buying there cuz my boyfriend is not available to fetch me to Damansara area anymore xD