in a corner

Ok, I usually don't post or ask for advise but I have an issue with my wife and cannot seem to find a way around it. We have been married for over 24 years. Bumps and bruises along the way with five kids. Here's the issue..for a while she has gotten into a deep praying mode, so deep where it lasts hours and it's a daily occurance. Actually to the point where she feels that her day cannot begin without hours of prayer time. To the point of the kids not getting breakfast, things not being done around the house (she stays at home and homeschools) and when I get home from work, I am second best on her schedule. Also, she is constantly on her phone with a female.group of women that discuss God and the Bible.etc...to the point where she forgets everything that is going on around her. Its actually to the point where I thought she was having an affair until I checked her phone. Although she's not having an affair with another guy, it's actually God, in essence. To me, it's come to the point of being unhealthy to our relationship. I don't have any issues with quiet time or if you want to. chat on the phone with your group but when dinners not done until 8pm, kids aren't being taken care of and the house is in disarray I think this is too much. I have tried to approach her but she automatically turns onto the defense and I'm the bad guy for accusing her...I'm at white end, I know how to talk to her, I know how to approach her, we've been married way to long for me not to. I really have no idea how to approach this one..any advise would be helpful and appreciated.