Who should be appointed as estate's administrator?

In all, given that the rule speaks of an order of preference, the person to be appointed administrator of a decedent's estate must demonstrate not only an interest in the estate, but an interest therein greater than any other candidate.The order of preference in the appointment of a regular administrator depends on the attendant facts and circumstances. In Navas L. Sioca v. Garcia (44 Phil. 711, 1923), the Court held that determination of a person's suitability for the office of administrator rests, to a great extent, in the sound judgment of the court exercising the power of appointment and such judgment will not be interfered with on appeal unless it appears affirmatively that the court below was in error.
In the case of Malbog v. Lejano (G.R. No. 212142. August 20, 2018), willingness to act as a regular administrator is not an issue considering that both Erlinda and Corazon are undoubtedly willing to serve as such. After a careful perusal of the records of the case, however, the court resolved to affirm the findings of the Court of Appeals (CA) that Corazon is more suitable to serve as administrator of Jose's estate.
With respect to Corazon, the CA found that she is qualified to be appointed as administrator of Jose's estate because, among the surviving heirs of Jose, she was the only one who had expressed willingness to be the administrator.
As correctly observed by the CA, Erlinda failed to show competent evidence of her filial relationship with Jose. Moreover, there was no evidence on record to prove her claim that she has an interest in the estate of Jose in the amount of P300,000.00. Nonetheless, assuming that Erlinda is a creditor, she would still be in an inferior position than Corazon who is a next of kin of Jose.
ADDITIONAL READINGS:
[1] Jurisdiction over settlement of estate - Project Jurisprudence.
[2] Arellano v. Pascual (G.R. No. 189776; December 15, 2010).
[3] 7 stages in settlement of estate - Project Jurisprudence.
[4] Rule 82: Precedence of Probate Will - Project Jurisprudence.
[5] CASE DIGEST: Ermac v. Medelo (GR No. L-32281. June 19, 1975).