Hello there, the problems that you are talking about arevery common with blended families. It takes a long time for blended families tofeel cohesive. Your girlfriend shouldnot take your daughters silence personally. Your daughters will warm up to yourgirlfriend with time. I think if she plans an outing just with your daughtersto do something like shopping or seeing a movie that will help out. I thinkboth of you will have to develop relationships with each child separately. Having a family day say every Sunday and gamenight for the family will help set a routine. Your girlfriend can find something she has in common with each one ofyour daughters and talk to them separately. I know that both of you come from differentfamilies that have different values. Ican understand how she would think that your daughters are being disrespectfulif she came from a family where children are supposed to talk to adults as asign of respect. In your family childrenmay have been encouraged to talk to adults but not seen as rude if they weresilent. In some families being silent isa sign or respect. We all interpret things differently because we are socializedso differently. You family (you and yourdaughters) have your own rules, regulation and culture even if you don't realizeit. Your girlfriend will want to alsoteach your kids her own values I think that will take time and should be doneslowly. You also will have to slowlybecome a step father to her daughters. Family units resist change, so if either of you push too hard the kidswill push back. Both of you have to be patient because the bonds with eachother's children take a while but they will happen. I don't see any majorissues in what you write just the normal frustrations that we all face with ourblended family. The work that you are both doing is very much worth it. Allkids will get used to both of you with time.
Keep doing what you are doing and things will change with time. Your daughters will see that their step mom will not take you a way from them. I also wonder if you need to have individual time with your daughters. I think daughters can be a bit posessive of their fathers and sons their mothers.
Given the right support, kids should gradually adjust to the prospect of marriage and being part of a new family. It is your job to communicate openly, meet their needs for security, and give them plenty of time to make a successful transition.