It is good to see a professional response. My basic advice is that this is not a DIY task. There are professionals for this. Use their services. Listen to this guy.
More immediately, patience is required. Even without considering the cerebral trauma, she has been through two major surgeries in a short time. That alone is exhausting. At this point the focus should be on rest and physical healing. Rehabilitation takes the back seat to healing the traumas.
The hospital should have a care plan that includes connecting you to specialists, such as an SLP, when it is appropriate and will not interfere with more immediate concerns. If the hospital cannot provide this assistance, you should explore options for transfer to a facility that can. They also should be a good source of information about planning for long term care. No matter how well intentioned the family is, this can be a huge burden and takes its toll. Yes, professional help for the family in this area is a good idea. Remember that to take care of her, you will have to take care of yourselves. This isn't a race you can power your way through; it may well be a life long process. Patience is the first skill you need to develop.
I wish you and yours the best, and hope the coming weeks bring you better news.