In the original version of the play (Shakespeare's) Macbeth and Lady Macbeth do not have any children. You might of watched/read/heard a different version...
Lady Macbeth is telling Macbeth to grow up and just kill the King. But Lady Macbeth tells Macbeth that she cant kill him since he looks like her father, this shows the reader that Lady Macbeth isn't as crazy as we think she is.
In a weird sense, the prophecy of the witches that Macbeth will be king does. It gets Lady Macbeth thinking that they should hurry things along.
because king Duncan looked alot like lady Macbeth's father.
Lady Macbeth was stricken with guilt. She was not actually "sick" but rather mentally disturbed.
father
Lady Macbeth says king Duncan resembles her father, so she encourages macbeth to murder him.
he reminds her of her father
Lady Macbeth cannot kill King Duncan because he reminds her of her father. She finds herself unable to harm him when she sees him resembling her father as he sleeps.
Lady Macbeth has at some time had a baby. Actually the historical Lady Macbeth did have a son who became king after his stepfather Macbeth died.
There is no mention of her fathers name only A sleeping Duncan's resemblance to him which prevents her from killing the Scottish king herself.
In Act 1, Lady Macbeth is the planner, the one who is dragging her reluctant husband into committing one murder. But by Act 4, Macbeth commits murder after murder and Lady Macbeth is the reluctant one, nauseated and consumed with guilt by the bloodshed. The roles actually reverse much earlier in the play, when Macbeth kills the grooms. That was not in Lady Macbeth's plan, and she is horrified by it.
In Act 1, Lady Macbeth is the planner, the one who is dragging her reluctant husband into committing one murder. But by Act 4, Macbeth commits murder after murder and Lady Macbeth is the reluctant one, nauseated and consumed with guilt by the bloodshed. The roles actually reverse much earlier in the play, when Macbeth kills the grooms. That was not in Lady Macbeth's plan, and she is horrified by it.