My dd(6) was similar. Got anxious and upset because she hated the numbing sensation and cardboard in her mouth (to keep the tooth dry) during her filling. We had to push to get it finished (dentist couldn't stop half way/ leave hole unfilled) Unfortunately, her distress meant dentist struggled to get a good dry surface for filling to stick to and it came out weeks later. More trauma for her (and me) having it redone despite best efforts to reassure her things wouldn't hurt etc and persuade her to open her mouth. Long story short more decay got in during this process and she got an abcess and had to have tooth removed under a GA and a 'space saver' put in to leave room for the adult tooth which won't come in for a while yet. I wouldn't wait 6mths- kids' teeth have less enamel than ours and decay moves faster. If your dd can't tolerate a filling in the chair you might need to do the general anesthetic. If not affordable is there a public dental hospital that would do it (without long wait)?