Continuing in Filioque’s perspective, there would be absolutely nothing wrong with your daughter taking a drink of water right after receiving Holy Communion either.
It’s a good idea to talk to your pastor about it. Your daughter has a legitimate need here that he should be made aware of and that should be addressed. If Father can be made aware of your daughter developing a potential fear of receiving Holy Communion I believe he would do whatever is possible to rectify the problem.
Sometimes, it’s the composition of the hosts themselves and not so much the mouth size that is the problem. I have, on occasion, received a host which was extremely thick and dry and seemed to cleave to my palate as soon as it was placed on the tongue.
For our long term and palliative care patients, we are able to obtain a host of special consistency which is very thin and dissolves quickly and easily. It’s a real blessing to those who encounter difficulty consuming the type of hosts which most parishes regularly use. With the patients who suffer from dysphagia (unable to swallow - or only with extreme difficulty) I’ll commonly give them a morsel of Holy Communion not any larger than the size of, say, the lead tip of a sharpened pencil.
The Church never intended for your daughter to go through what she did today.
Here’s a little excerpt taken from paragraph # 8 of Inestimabile Donum, the blue text should be of interest to you:
Instruction Concerning Worship of the Eucharistic Mystery
Sacred Congregation for the Sacraments and Divine Worship
Approved and Confirmed by His Holiness Pope John Paul II April 17, 1980
8 …The preparation of the bread requires attentive care to ensure that the product does not detract from the dignity due to the Eucharistic bread, can be broken in a dignified way, does not give rise to excessive fragments, and does not offend the sensibilities of the faithful when they eat it. The wine for the Eucharistic celebration must be of “the fruit of the vine” (Lk. 22:18) and be natural and genuine, that is to say not mixed with other substances …]
I would say, your daughter’s case even surpasses “offending the sensibilities”.
…Will be saying some prayers for you and you daughter Tracy24.
God bless you and those dear to you