*update* Old bassinet mom gave me advise

So I had a halo bassinet on my registry which was marked as purchased. I figured my mom found one on fb used and was excited. Come baby shower she rolls out her old bassinet from when she was a baby. Now I'm not saying I don't like it and I'm not appreciative but it's very very old. Lole old rusty springs on bottom looks like a mini crib. The mattress is so thin and squishy with the springs that I'm worried about my baby sleeping in it. I already have extreme anxiety and this doesnt help. I tried to nicely say "hey u should keep this at ur house for him if he ever needs to nap or sleep" and she was almost in tears. She said she worked 2 months on restoring it and painting it and was upset that I didnt like it. I tried to explain to her that I liked it and just thought she might need one there. When she brought it to my house i showed her how squishy the mattress was and that it was not safe for new burns to sleep on a soft mattress and she said "that's the only one I could find to fit it. It's an antique and they dont make mattress for those anymore. Just put a board under it. I slept in it and u and ur brother did and ur ok" ugh I'm struggling. I dont want to hurt her feelings and not use it but it's not safe. There is like a 1 in gap with the mattress in there already and I'm having anxiety. Please no judgment or negative comments. Anyone have suggestions?

*update*

So I asked my obgyn on Thursday at my appt and she said not safe to use. My mom came over on Saturday and she was in my room asking why the sheet wasnt on the bassinet. I broke down told her dr said it's not safe and bla bla. She stated raising her voice saying "I used the bassinet, u used it and ur brother did and u turned out fine. It's an infant, he not going to move when he is in there sleeping." I simply said it's not safe, guidelines have changed and I'm sorry. And she yelled again the same thing she said and then said "I worked on the for 3 months for nothing. Fine I'll fucking take it back" and she stomped out crying and say in her car. I feel absolutely horrible. I know that it's my baby and babys safety and that's all I should care about but my mom just has this way of make me.feel awful. I cried to my husband that I felt so bad and that we should just but a matress that fits it which would have to be costume made and cost $50 but baby is due date is 3 weeks away and he could come anytime now. I just feel awful. 😔