Thank you so much for everyone's thoughts and input so far, it is really helping me trying to see things from multiple perspectives.
I am new to this type of forum but trying my best to answer everyones comments and questions as I do appreciate it.
My MIL and husband don't have a close relationship, they are all about the younger sibling who I guess is the 'golden child'.
We have popped in to see them but it was in most instances us having to initiate it.
I do not agree with many of my MIL's opinions which I would go as far to say that I find them rude at times, BUT although she is very opinionated I genuinely just let them wash over my head.
I at times have been in situations with her when whatever I have said has basically just been disregarded to suit her.....and I have not made a fuss to avoid conflict. As an example, when my daughter was still quite young I asked her if she would mind watching her for a few hours at our home, I asked nicely and mentioned that if she could just stay home, spend time with her and look after her that would be a massive help (I had several appointments I needed to attend). When she arrived I gave her a quick run down just with basics such as last bottle, next bottle, nappy change etc and she commented with 'I am sure i am capable of looking after a child'. I had also specifically mentioned that I would rather they stayed home as weather was wet and windy and was met with a 'I can't just sit in and do nothing so we are going to go out' Out was on foot in a pram in the rain to basically parade my daughter to people she knew locally.
This is just one example but there have been lots more. So yes, there is certainly some dislike but hand on heart I am genuine when I say that I wouldn't stop her or make it extremely difficult for her to see her grandchildren. I am still polite to her, still will put the kettle on for her and be mindful of my words despite her being quite rude at times.
The children don't really ask about her and don't show much interest at all.
She treats them different which is noticeable and to the point my stepson actually sticks up for his younger Sister....he is quick to point out she is also very special!
We have been out together in the past but again there is little interest.
She only seems to show an interest if it involves her taking them by herself for a day trip (and she has inadvertently mentioned meeting with her friend...so it feels purely for show).
This may sound odd but of she just actually showed interest, popped in, played with them in their home environment and actually got to know them, I then would genuinely consider letting her have a day trip.
She does not ring, text, or even know what they like/dislike.
All I am wanting is her to spend time building a relationship with them before day trips out are discussed. I do have concerns about how she dismisses my thoughts at times and am certainly not ecstatic about having to discuss this with her but I can only try I guess.