Today she texted me and asked me to look up an address for and I casually mentioned that I really like the crate and want to know where she got it so I could get more for him. She told me a female coworker bought it for him. And for whatever reason I texted back oh that’s nice tell her thanks and by the way I didn’t know her name to change to Steven. You came up with that lot real quick. She hesitated and texted back yes she did lie to me because she knew at react this way and she didn’t want me to throw it away. I told her how disrespectful I thought it was for the man that’s destroying my family to send my son a gift.
Of course she is going to lie.
I think the way you went about it was very passive aggressive, you were trying to trap her. I think it is better to be direct and say exactly what you want. For example, you could have said, "I was suspicious where the tinker set came from so I checked and it came from OM. I do not think it is appropriate for the OM who is breaking up a marriage to send our son a gift."
This might not be the best way to say it, but hopefully you get the idea.