I didn't see the programme, so can't comment on the content but I can comment on the process. The filming process is done in rough chronological order, so the 'reveals' are happening there and then. Filming is done over at least a week, and the prior research is done over a period of around 6 - 8 months. During the research period, a 'story' is worked out, and filming is done to reflect this. However, when it comes to cutting the footage down to only an hour, there are lots of strands and information which obviously has to be cut, and this can lead to the final episode chosen seemingly having lots of loose ends.
She will have found out a lot about her family, but we may not have seen it all. And as for hiring a professional researcher to use Ancestry, they will have been there as a guide to show how it's done. How many of you were experts at using online databases when you started your research? The individuals are chosen because they don't know anything, haven't done any research, and don't know how to go about it. Yes, they might be spoon-fed the information, but it's all been thoroughly researched and at the end of the day this is only an entertainment programme, not a how-to guide or in-depth look. If it was, each programme would be about 4 hours long.