Hint was associated to mother
Record was a death certificate for a child
Mother was listed on the death certificate
With one possible exception to be discussed below, accepting a hint doesn't actually bring anything about anybody into your RM database. My work process for a hint is to create or fetch all the facts and sources and citations and media files suggested by the hint. These facts and sources and citations and media files can be associated with several different people including people not associated with the yellow light bulb. The yellow light bulb is just to alert you to and point you to the hint. After I have processed the hint and extracted everything from it I can, I accept it to make it go away so I don't process it again. Of course, it doesn't go completely away. It just turns from yellow to white. After you are done with the hint, there is no real link from the hint to anybody in your database and never really was. RM doesn't store anything about the hint in your database and the hints cannot be searched in any way or printed out or anything like that. And the reason is that they really don't exist. They are just some ephemeral nothingness that you can use as links to data that you can see and that RM cannot see. Think of it this way: when you are done with a hint, you found the data. You could have found the exact same data without the hint, but maybe the hint gave you a little help.
The exception is that ancestry.com Webhints are real - there is really something there. But where the "there is" is really in ancestry.com, not in RM. In addition, TreeShare does provide a mechanism to assist you in bringing the hint data from ancestry back into RM. I do use TreeShare and I do use ancestry's WebHints. But I don't use TreeShare to bring the hint data back into RM. I do that myself, just like I do with the WebHints from the other sites. So somebody else might need to help describe how you can automate getting death certificate data for a child into RM using TreeShare and how you would then get the data connected to the child's mother.
Here is how I would do the whole thing for the death certificate. It doesn't matter whether I found the death certificate with a Webhint or if I found it some other way. I would create a fact for the child called Death Certificate. If the child didn't exist, I would have to create the child before I could create the Death Certificate fact for the child. I would then transcribe the death certificate into the note for the Death Certificate fact. Then I would create a citation which would include the same transcription of the death certificate and I would link the image of the death certificate to the citation. My initial creation of the citation would be for the Death Certificate fact. Finally, I would Memorize and Paste the citation every place it needs to go. If it was evidence for the mother's name, I would paste the citation to the mother's name. If it was evidence for the mother's birth place, I would paste the citation to the mother's Birth fact. I would continue pasting the citation until I was done - adding facts and people as needed. Most of the pasting would probably be to the child himself or herself - Birth fact, Death fact, Burial fact, etc.
Most RM users probably wouldn't have a Death Certificate fact. They would start the process I just described instead with the Death fact itself. But I like having a Death Certificate fact which is separate from the Death fact. But the idea is the same. Develop the citation once including any transcription and media, and then Memorize and Paste it everywhere it needs to go, and creating the "where it needs to go" if for example you don't have the child's parents in your database, etc. If I had found the death certificate without using a WebHint, I would be done. If I found the death certificate using a WebHint, I would approve the WebHint to make it go away and it wouldn't matter in the least which person the WebHint was originally for.
P.S. This note is too long and I'm about to go a little off topic, but it seems to me that RM does not have a very good place to attach a citation that is evidence for a person's name or for their parentage. For name, it's not unreasonable to attach the citation to the person's general record where their name is listed in the Edit Person screen. But I prefer a Name fact instead. I suspect most users would not like my Name fact and would just attach the citation for evidence of a person's name to their general record. For parentage, it seems to me that RM really has no reasonable place to attach a citation that is evidence for a person's parentage so I create a Parent fact. This fact does print in narrative reports and it does provide a place to attach a citation for the evidence of a person's parentage.