I do not have a clear opinion on what has happened to Celina. However, I do have a view on how LE should have proceeded, but do not know if they did so.
I agree with various posts that it is inconceivable that there is nothing known within the church and it's members. Either someone within is responsible (for the pregnancy, her disappearance or helping her run), or has information which will help point LE in the right direction. So the question, with a cult of this sort, is how LE can gain access to that information. The weak point of the church and it's leaders are it's antecedents. In 1991 it was thrown out of the Christ Gospel Ministries International (a large Pentecostal umbrella organisation) because they had questions about Cerita Smith's personal control over her members and about the financial management of the church, including how they raised and used funds (especially interesting given that Celina's father (and Cerita Smith's brother) was the church accountant. It takes one hell of a lot of doubts for a church group to, effectively, excommunicate a member church. These concerns may be magnified by the background of the family. I am confident (but not 100% sure) that Celina's father, Crezonzo J Mays, is the same as Crezonzo Jerrel Mays who died age 65 in Florida in 2017. If this is the case he had a record a mile long from the 1970's and 80's, involving drugs and robbery. Given this background I would expect LE to have focused on finding issues in the church, probably around finances, and used this to place pressure on the family. I would also expect them to have closely questioned Barbara Young, the attorney who investigated complaints leading up to the expulsion of the church from it's parent organisation (in order to identify anything she found out which could be used). Was the church being used as a front?
It would be interesting if anyone knows to what extent LE went down this path.