If there is proof that the husband's money was used for purchasing the property which was registered in the wife's name, it is better to obtain the husband's affidavit expressing his consent for sale of the property by his wife. If the husband is no more, their children have to execute an affidavit.

Both husband and wife involvement is must. Children has no say.

The land is in the name of the mother so only she has rights over it and she can sell it.

Father's affidavit need not be required as the land belongs to her.

Regards 

He will be include as seller along with mother.

Property bought by husband in wife name is for benefit of joint family 

better take consent of husband and children 

No permission, affidavit or consent required

If it is name of wife that is the mother she can directly sale it no permission from kids or husband.

See as in there is no need for you safety you can take signature of husband as witness.

She is absolute owner she can sell without consent of husband and children's. But better at time of registration take husband and children's as a witnesses. 

Affidavit not required 

No if its her self acquired property in her name of permission is required

1) If you are directly going to make sale deed than only mother's signature is going to require.

2) If you are going for Agreement to Sale than kindly take signatures of her husband and children also for you safety.

1. As per the information mentioned herein, makes it clear that the property was bought in the name of the mother by husband using his hard earned money.
2. The nature of property is self acquired in the hand of mother, children can’t even think of getting any share in it without the mother consent and permission.
3. But, yes, to avoid any future problem, father should give his NOC only so that in future he can’t claim any share in the property and that is also as the property was bought by his hard earned money.

Affidavit is necessary. Mere witness to the sale deed will not serve the purpose.

Since the landed property is on the mother's name alone, it becomes her own and absolute property. As per law she need not obtain permission from her husband or her children for from anyone to sell this property to you or to anyone of her choice.

Nobody can legally question her authority over this property for whatever the reasons.

No affidavit is required from father because ther is no law mandating  any such requirement, getting him as an attesting witness is also a choice and it is not a legal requirement