I should preface this by saying that I'm not a midwife, nor am I an expert in this area. However, this is my understanding:
If you do choose to go the Certified Nurse Midwife route, then yes, you'd need to complete an RN program and then a CNM graduate program. It would likely be less expensive for you to complete a 2-year community college associates degree program than an accelerated bachelors degree. You could also consider direct-entry CNM programs, which are basically the bachelor's RN program and master's CNM programs combined; they tend to be a bit faster, but a bit more expensive.
Your other option, which I know even less about, would be to do a 'Direct Entry Midwife' program, which is a midwife role for people who are not nurses but are still licensed. This could be an appropriate option for you; however, they face far more restrictions than nurse midwives, and they are only allowed to practice in certain states. In contrast, CNMs (nurse midwives) can work in all states, and in some states they can work without physician oversight and have full prescriptive authority.
Doing a cursory search, this site seems to have pretty comprehensive information about becoming a 'direct entry' (i.e. non-nurse) midwife, including the laws regulating midwives in each state:
State By State | Midwives Alliance of North America
Just to clarify something that may be confusing due to the terminology: In the US nursing world, a 'Direct Entry Masters Program' means a Certified Nurse Midwife or a Nurse Practitioner program where the Bachelor's Degree for your RN and Master's Degree for your MSN are combined into a single three-year program. By contrast, this 'Direct Entry Midwife' role is a completely non-nursing role. Please realize that the 'Direct Entry Certified Nurse Midwife' program and the 'Direct Entry Midwife' program are two completely
different things, even though they have almost the same name (which is ridiculous); the former awards you both an RN and a CNM license, whereas the latter awards you a non-nursing license.
You may get some helpful perspectives if you pose this question on the OBGYN forum under specialties; I'm sure they know more about the different types of midwives than I do.
Unfortunately, you may find that some managers would be hesitant to hire you for an L&D RN position, despite your experience. Given the fact that all of your experience is in the provider role, they may be concerned that you'll have a hard time transitioning into the RN role (and specifically not overstepping your scope of practice). For that reason, if you do go the nursing route, you may have the best experience if you just do a 'Direct Entry CNM' program (since you'd skip the bedside L&D nursing altogether and go straight to a midwife role).
Congratulations on your marriage and welcome to the US!