Step child unless adopted by his step parent can not inherit him. 

Step children can inherit only hus biological parents  

If your father is not the biological father she has no share in your deceased father property 

No. She is not.

Yes both having same father and you can also identify the class of heir

1. No. Step Daughter CANNOT claim anything from her Step-Mother's property, in anyway, whatsoever, without any exceptions.

2. However Step Daughter CAN claim her share of property from deceased biological Father, in EQUAL proportions. 

Yes, she is entitled ti get the share of the property.

Regards

No she is not but she is definitely legal heir in the property of your father.

1. If your step-sister is not legally adopted by your mother she has no right in your mother's property. 

Your step sister, if born to your father can become a legal heir to your father if he is not living, but in any case she will not become a legal heir to your mother neither she will be considered as a successor in interest to succeed to the properties of your deceased  mother.

No, your step sister is not legal heirs in the your biological mother's property share.

- If the said property came to your mother after the death of your father , then she can claim right over the property left by your deceased father .

- But, if the said property is in name of your mother , even purchased from the fund of father , then legally the step sister having no right on her property , specially when your mother has not adopted her legally. 

Not in your mother property if she was not legally adopted by your mother.

1. If there's a registered Adoption Deed for the same, then your step sister from first wife of your late father, will be one of the legal heirs of your mother.

2.  If there's no registered Adoption Deed, then your step sister will not be legally entitled for a share in your late mother's property.

If your mother didn't adopt her then she is not an heir to the property.

No. She is share holder in her mother's property 

No she is not legal heir in property of your mother.

She is only legal heir of the fathers property if it's ancestral. If your father has self acquired property and only if he will in her favour or dies intestate then it's possible to get share. If the property is self acquired of your mother only if mother consents she can get it or if mother willed or died intestate

Dear Sir/Madam,

The step daughter is definitely the legal heir of the mother as asked by you. 

yes, Biological Children's are class1 legal heir. 

No. She is not a legal heir given the circumstances you have explained in the question dated 09.09.2020.