S.H.
Well in addition to what Deanna Leigh said....
basically, your daughter's "world" has been turned upside down by the introduction of her sibling.
It is not only you that had a baby, your daughter "had a baby" too.
When a child is "stressed" or anxious... they regress. This is one symptom of their emotional well-being or not. She is waking a lot and crying for you... this is a regression. BUT ALSO, she is 2 years old... and this comes with the territory.
Just think... put yourself in her shoes... it's really NOT easy for a child going through the 2's stage... it's hard on them too, they don't do things like this just for fun or to irk the parents. This is "growing pains." PLUS, she had, 4 months ago, a SIBLING dropped into her life. AND, Mommy is now busier, not as focused on just her, is tired, is tending to baby more.... and it makes the eldest sibling feel "marginal."
Children sometimes take a LONG time to adjust to life's upsets... give her time, give her comfort, give her understanding, give her patience. You want her to TRUST you... forever... and that this incident will not set her up for angst in the future.
This stage is full of natural transgressions, and adjustments. ALSO at this age, their "emotions" are not even fully developed. and they cannot understand all the abstractness of it at this age. Their "impulse control" is not even fully developed either.
She will get back to normalcy, once she feels happy again. Or at ease about her life.
One thing I would not do, (not saying you are), but there is no need to "punish" for this, or be punitive about it all. They need HELP from their Parents... if you must bring her into bed with you then fine.
OR, an alternative would be, to get a futon mattress for the floor in your bedroom, and let her sleep there. That is what we do with both our kids. It works for us, and them.
My girl was also like that. Then she grew out of it. I've learned, that you can't always "make" them sleep all night until they are ready. Yes, you can try things, rewards, punishments, putting up gates in their doorway etc. But, in the end, they will still get up, search for you, come to you for what they are feeling and want to be with you. They are just a child. It's okay.
Also at this age, they begin to have night-mares and develop "fears" about night-time or the "boogey man" and the dark. This is all NORMAL developmental stages. They can't help it... but they NEED us to help them navigate through it. We are their "guide" through the unknowns that they are anxious about.
Your girl has a LOT on her plate to adjust to and deal with. It takes time.. it's her age, and her new sibling, and her Mommy has another baby to tend to, and the crying of the baby, and everything. Whoa... what a world to carry on such little shoulders....
Not all children sleep perfectly from day one. That is the exception. The reality is, most kids wake up... they are changing, their parents are changing in relation to their development, and EXPECTATIONS upon them are getting higher. WOW! How overwhelming for a 2 year old! An "eldest" child, whether or not they say it, has a LOT OF pressure and new expectations upon them.... just because they are the oldest they are by default, "expected" to behave, be perfect, be an example to the baby, read their parents minds, and do everything.... but, they can't. They are not "ready" for all this. It's hard for them.
Give her time. It'll be okay. She has a whole childhood to fulfill yet.
All the best, sorry for rambling,
Susan