Farrah tells TMZ ... she went with her daughter, Sophia, and her friends to an "all ages" concert at The Empire Control Room in Texas Monday, thinking it would just be safer if she were there -- referencing last year's Astroworld tragedy. Farrah's been getting slammed ever since posting about the event, with many assuming the 13-year-old was under the venue's age limit and that it was wrong to take a 13-year-old regardless.