I would talk to your partner and maybe he can help create a bond with you both.

Reading this question again I think it isn’t that strange as your husband is her biological dad and she’s about to become a biological mum herself and has a closer connection with him pure by blood. Don’t take it too personal ! Besides the blood bond we have different connections with different people. Growing up I had 4 sisters and there was only 1 I felt for sharing deeper emotions with; this doesn’t mean I loved my other sisters less, just different connections

I think a lot of this depends on the relationship you had prior – have you been a step mum for 20 years or 2. maybe take her on a special date to talk baby?

No offence, but you are the step parent, isn’t it natural for your step daughter to go to her biological parent for help?

How old is she?
Communication is key.
Could also be her hormones making her feel a certain way, but you won’t know until you ask.
Otherwise just let her talk to her dad and she may be different when baby comes along

It possibly depends on how long you have been a part of her life and how close you are to her. It is natural that she would want her Dad’s involvement – It’s her Dad. If you want to be involved in something that is huge in her life, then as the step mum – you’re the one that’s most likely going to need to make most of the effort,

It’s probably just a natural reaction for her. Maybe ask if you can throw her a baby shower and try and become involved that way.

What was your relationship like before this? If you weren’t that close, this situation shouldn’t be a surprise. However, if you two were close and she’s now shutting you out, have you tried talking to her about it?

being a step parent is hard and one may be fearful of overstepping the boundaries however try and have a chat with her. Explain to her that you would love to be involved more and let her know she can always come to you for anything. Hopefully as she gets further along in her pregnancy she will involve you more. Let you partner know that its hurting you also, without creating any rifts.

maybe speak to your partner and see if he can involve you more

I wonder why she goes to her father more? Has there been a rift between you previously?

Approach her. Maybe she feels like you wouldn’t be interested. New mums always want/need help. Unless you have a difficult or trying relationship then she would probably be greatful. You could buy something small of what she likes for the baby to show your excitement?

I agree that the best thing to do is to talk to her, explain how you feel and show her that you are willing to help her. If you don’t try to change things, they will never change by themselves.

i would try and make conversation with her about her pregnancy and let her know that if she needs anything youre happy to help. but i think you need to get over it a little. obviously i dont know your relationship with her, but maybe shes more comfortable asking her dad for things

That is sad and I can understand it hurts. Personally I would try to have a chat with her and show her your feelings.