this is my first visit to mumsnet, and i am so glad i saw this thread.
i am married to a widower; he has two kids, my DSD16 and DSS13. we also have our own daughter who is 1 year old.
i get on pretty well with DSS13, and i love him....but have lots of conflict and struggle with (well - not WITH so much as OVER!) DSD16. like other posters have said - she sees herself as the wife and the head of household. it has been rough going from the start of our relationship, because DH overcompensates and treats her like a spouse...except it is not even that, because at the same time, he treats her like a seven-year old girl; she doesn't have any responsibilities and acts like a small child, but is empowered like an adult. he won't say NO to her about anything...on the rare occasion that he does discipline her for anything at all, he feels so guilty he ends up 'making it up to her' by letting her have her way about something else. she bullies me and her brother, and i admit i am no good at standing up to her either; i feel like it is not my home most of the time.
i came on here today because i just don't know what to do anymore. she is really over-bearing when it comes to my DD1...and if DH is left to look after the baby while i try and do a bit of work, DSD16 latches on and won't leave them alone. i don't want her to have this 'special relationship' with my baby girl, i just want her to be her half-sister and not try to be her mom or my DH's partner...i am sick over it and DH does not understand, just thinks she is acting like a "big sister", but it isn't like that.
she won't even call the baby by her full name, because she doesn't like it (it is my mom's name) and so she uses a shortened version that makes it totally different.
i find it really hard to LIKE her even though i think i do love her in a way. and it is a constant source of trouble in my marriage. we do see a counselor (DH and I) and i also have been seeing a CPN since the baby was born because i think i have been very depressed...but it isn't enough.