Sorry to be confused here, but I fail to see how the information your SIL is giving you can possibly be accurate.
Okay, let me say this: I'm not a doctor, so PLEASE someone (or you) verify this, but I'm fairly certain the information I've got is accurate.
1. No one precisely knows the "cause" of SIDS. Some people suspect it may be due to a brain stem issue that causes too-deep sleep from which the child essentially never awakens, et cetera.
Certain factors seem to aggravate SIDS such as smoking, face sleeping, et cetera, but they also don't "cause" SIDS.
2. I fail to see therefore how the co-sleeping could "cause" SIDS, particularly since (as you know), co-sleeping tends to be a preventative measure for SIDS anyway.
3. If they accidentally suffocated the baby, this would make more sense to me, but accidentally suffocating the baby is not the same as having the baby die of SIDS.
4. The baby may well have died of SIDS while cosleeping, but there's a difference between cause and coincidence. For the record (another example of false reasoning here), most babies who die of SIDS sleep in cribs, but that doesn't mean cribs cause SIDS.
What I would do is clarify exactly what did happen in case she has her facts wrong. Moreover, if the issue is one of accidental suffocation, maybe you can show her what you're doing to prevent it and to sleep safely. I don't know if you're using a cosleeper attachment thing that goes on your bed, or whatever, but that might alleviate some of her anxiety.
Good luck!
Okay, let me say this: I'm not a doctor, so PLEASE someone (or you) verify this, but I'm fairly certain the information I've got is accurate.
1. No one precisely knows the "cause" of SIDS. Some people suspect it may be due to a brain stem issue that causes too-deep sleep from which the child essentially never awakens, et cetera.
Certain factors seem to aggravate SIDS such as smoking, face sleeping, et cetera, but they also don't "cause" SIDS.
2. I fail to see therefore how the co-sleeping could "cause" SIDS, particularly since (as you know), co-sleeping tends to be a preventative measure for SIDS anyway.
3. If they accidentally suffocated the baby, this would make more sense to me, but accidentally suffocating the baby is not the same as having the baby die of SIDS.
4. The baby may well have died of SIDS while cosleeping, but there's a difference between cause and coincidence. For the record (another example of false reasoning here), most babies who die of SIDS sleep in cribs, but that doesn't mean cribs cause SIDS.
What I would do is clarify exactly what did happen in case she has her facts wrong. Moreover, if the issue is one of accidental suffocation, maybe you can show her what you're doing to prevent it and to sleep safely. I don't know if you're using a cosleeper attachment thing that goes on your bed, or whatever, but that might alleviate some of her anxiety.
Good luck!