Yes, you may submit surety bond as directed by the Court, where there is no requirement of a professional lawyer if you are acquintted with it.
What is alleged crime have been committed by you and your sister where a case / FIR is stated to have been registered and taken cognizance by the Trial Court u/s 506 IPC which reads as:
Section 506 in The Indian Penal Code
506. Punishment for criminal intimidation.—Whoever commits, the offence of criminal intimidation shall be punished with imprisonment of either descripttion for a term which may extend to two years, or with fine, or with both; If threat be to cause death or grievous hurt, etc.—
And if the threat be to cause death or grievous hurt, or to cause the destruction of any property by fire, or to cause an offence punishable with death or 1[imprisonment for life], or with imprisonment for a term which may extend to seven years, or to impute, unchastity to a woman, shall be punished with imprisonment of either descripttion for a term which may extend to seven years, or with fine, or with both.