Well, I'd say that at the end of season 6, Henry is probably around like 14 or something? That means when Emma got married she was around 32. In season 7, Henry is canonically 29, so by the time Emma had Hope she would've been 47.
I hope I got all that right (har har)
According to the Black Fairy in 621, Henry is fourteen at the time of Emma's wedding... We also know that he leaves Storybrooke shortly after graduating senior high school. However, it is never stated how many years he was away before being reunited with Emma in 702, nor is it ever stated how old he is when Emma becomes pregnant with Hope. There is no canon age for him here; I have no idea where you got the number 29 from.
Lucy is at least eighth; a major plot point in "The Eight Witch" is that the Dark Curse will be cast when she is eighth years old. However, it is important to remember that, as seen in "A Pirate's Life", Emma became pregnant before Henry married Cinderella and fathered Lucy, so Henry's current age isn't relevant to when Emma had Hope.